The answer is none: only the empty set of answers is consistent.
I find it a bit of a disappointing puzzle, it tries to be clever but has an uninteresting answer. In essence, it is about as interesting as:
What is the capital of Germany?
A) Paris
B) London
C) Düsseldorf
D) Miami
There’s just no answer among those provided, since Berlin is the capital of Germany.
Let’s try to come up with something that is a bit more satisfying.
If you pick an answer to this question at random, what is the chance that you will be correct?
A) 1/3
B) 2/3
C) 2/3
This seems a lot more self-referential to me. If none of the answers are correct, then indeed none of the options have the correct answer. If only one of the answers is correct, then A is correct and B and C are not. And if exactly two of the answers are correct, then B and C are both correct.
So, the answer is either none, only A or both of B and C.
I think that was the joke.
I like jokes to be clever 
I think the paradox was supposed to be the clever part 
Also an element of expectation subversion
If there was a neat, tidy answer, it wouldn’t be as noteworthy.
It’s not a paradox, just like the question about the capital of Germany is not paradoxical. It would be paradoxical if it included “0%” among the answers, but it’s not even clever enough to include that.
And there is a neat, tidy answer: it’s none of the answers that is provided, hence that is the answer.
What I find mostly annoying is that it has the potential to be a funny or interesting riddle, but this potential is unused.
It’s a kyu riddle, not a dan riddle. 
I also came to your conclusion that three answers would’ve been even cleverer (is that a word, cleverer?) but nonetheless I enjoyed the self referencing wrong answers.
The 25% and 50% options are fighting each other too.
That could’ve been better, but I enjoyed it anyway.
I wish I could say the same for drawings and paintings! That’s quite frustrating: I can’t really enjoy mid level art pieces, only masterpieces, but that means I miss a lot, a LOT, of enjoyment, since there’s plenty of amateur artists all around, producing a HUGE amount of “nice” pieces of art.
I have friends that really enjoy them and they’re WAY happier than me! 
I lost one full point (on a /20 grade) in an English test twenty years ago, for writing “cleverer” instead of “more clever”. It stung, but on the plus side, I remember.
BTW, have you seen the film “Dumb and dumberer”? Dumberer is definitely a word.
Might be a British/US English thing. I feel like more clever is more correct but cleverer is becoming correcter…
English language rules are amazing: you add “er” for one syllable words and… for two syllables words that end with y !!! (really??? reallier??? 
)
Nothing fancier? No moon phases involved?
In other cases “usually” you must use “more”.
“Usually”??? Can you even use “usually” in a “rule”?
I must be too aristotelian for that.
Memory can be deceiving. It turns out what I lost a point for was not “cleverer” but “easierly”. Apparently the correct form is “more easily”.
English grammar rules are a bit arbitrary as the language is constantly evolving. When neologisms or new usage patterns, some will assert that they are incorrect, however anything with enough time and users usuallier becomes accepted as valid and possibly even the newerly preferred usage.
As Ernest Fenollosa said, “A late stage of decay is arrested and embalmed in the dictionary” (“The Chinese Written Character as a Medium for Poetry,” p 74, Washington, DC, n.d.). In my professional experience, many neologisms are useful additions to the language, but corruptions generally undermine the structure of language and promote incoherence of expression.
Easily has more than two syllables. Otherwise it would’ve been “easilier”. 
Just like happy - happier.
I find “easierly” quite bold in its way of subverting the order in the sequence of modifications.
Morely easy
