I would say the 1st one is the only one correct. The 2nd one should be who, the 3rd one should more and likely be whom, and the last one should probably be who. I don't know if I'm 100% though. I hope I helped.
I think grueling means extremely tiring or demanding
I'd say 3,4, and 5, but an argument can be made for 2. Also Hans Zimmer is an international treasure. Hope this helped.
I believe that it would be B.
