>>14015134(a) is false. I depends on B and M, so you can't say they're I, B, M are independent
(b) is true since any path from I to J has to pass via G and in all cases the connection at G is head to tail, meaning that G is blocks each path.
(c) I guess it is true since all the relevant info about J is contained in J. I don't know how to prove it strictly.