Without context, I would say only answer a. If you added "usually" to the sentence, only then would answer b sound ok. Simple present is used with habits and in statements of fact. The progressive is used to describe actions in progress at the moment.

"What do you try to draw?" Would be fine in the context of asking a question about a specific situation, for example if someone said "I go to a class that teaches me how to draw." Then you could ask "What do you try to draw?" and it would be fine.

I agree with Stephanie ‚Without adding any word else ‚I would choose (a). But if you add "often‚ usually‚.." We should choose (b). But now it seems both are correct with slightly desire to be more accurately the (a) choice than the (b) one

Yes I think both are OK.