Automata: Context free Languages

Hello, I have been unsure of this problem for a while and was wondering if someone can help me out. Please explain how you came to your conclusion as it would be very helpful! Thanks!

Let L be the language of the grammar: S AB A aAb I aA I E B bBa c The operation mir returns those strings in L such that no proper prefix is in L. Determine the language min(L) and identify in the list below the one string that is in min a) aabbbbca O b) aaaabca O c abbbbcaa O d bbbcaaa