Based on your research for tuesdays with morrie, describe how these circumstances would affect a person’s identity development (crisis, commitment, diffusion, foreclosure, moratorium, achievement.)

That was SUCH a lovely book! Probably one of my favorites of all time. 
I assume you're talking about how it would affect the main character Morrie, yes? 

Well Morrie is suffering from Lou Gehrig's disease.This disease is also known as ALS or amyotrophic lateral sclerosis. It's a nervous system disease that weakens and deteriorates muscles and impacts physical function. It would really impact Morrie because he used to love dancing before his disease, which he sadly can't do now. Also it could affect his identity as a person if he doesn't handle the news of his sickness correctly. His whole being, his personality, everything could be affected. 

Dshould be the answer