D.
I have a 3 month old daughter and she has been sleeping in her crib all night for about 4 weeks now. I put her in the crib to take naps the first week or so before so she wouldn't get freaked out about the concept. She does great and I wouldn't have it any other way. I had a harder time letting her sleep in the crib than she did actually being in the crib. Trust me, transition to the crib ASAP and after about the first week, you will wish you put them in the crib earlier...