If I had to pick something out (from those four choices) as "incorrect", I would choose (c). Still, as I said before, I am reluctant to state unequivocally that it's 'wrong'. I would not expect to find 'very wonderful' used in formal English. And I think it could be worded much better -- even in more informal English.
I think of adjectives such as 'dead', 'perfect', pregnant', 'unanimous', 'unique' and 'stationary' as being absolute. In other words, they are words that don't use comparative and superlative forms. However, this 'absolute adjective' rule is not ironclad.
For example, you'll hear things such as 'She's very pregnant' in everyday English to mean that her pregnancy is at an advanced stage and thus it is also quite obvious that she is pregnant.
Another example might be this: If I go with friends to a party, but the party is dull, my friends and I might leave, giving as a reason that the party was dead. If we then go to a different party and find that there is even less action going on there, then I may well say that the second party was 'even deader' than the first one was.