Who should I go for?

Hello everyone, so I have come across a little bit of a problem, sort of. I’m 16 years old and I like 2 different guys. So the first guy I’ll call him guy a, he’s a freshman in college and I’ve met him in person he’s actually best friends with my friend, so that’s how I met him. He’s like the perfect bf on paper and he’s so respectful of my decisions. However he is 18 and I don’t know him very well. And boy b, we go to school together he’s 1 year older than me and I’ve liked him for over a year now, he’s changed my life and I love him for that. We used to ft every night for 9 months for at least 5-6 hrs, but then that stopped when a girl in our school took her life and it was a really rough time. He’s honestly also the perfect bf, and I just really like him. The only downside is that he’s dying of cancer, and he said he doesn’t want me to get hurt, but I have no idea how long he has left to live. So I really like both guys but I have no idea what to do? Please help me!!