I'm an ESL teacher, and I'm having a difficult time deciding if these sentences are grammatically correct or natural:

1) A: "What is fun for you?"
   B: "It is to play baseball."

2) A: "What is the important thing to you?"
   B: "It is to play baseball."

I think the second one is more natural, but are they both grammatically correct? I would naturally use "playing" in both scenarios, so I'd gladly accept any opinions!