Potential Internship this summer questions...

[RivaLiva]

I have a dilemma right now that I need some advice on. Company A is my absolute #1. They brought me in and interviewed me and the whole experience was amazing and I really want to work for them. They have told me they will know early next week. The HR person I talked to Friday said They have finalized some positions but I am still in the running for others. I forget the exact wording.

Company B has offered me an Internship position for this summer. I am not as excited to be working for them, mainly because company A is my dream company. They gave me a deadline of this Monday that I got extended until tomorrow(Wednesday March 28). The HR person I talked to here said they were considering another candidate so I don't think he will extend it any farther.

Which would you choose?

I don't want to decline the offer and end up with no internship for the summer because I didn't take the sure thing, but I also don't want to take the offer and get accepted to Company A and have no way out of Company B.

I also don't want to choose company B and then screw them over if I do get accepted by company A, because that doesn't seem honorable.