b and d becuaseregard is the last one and respect is the second one.
D. is wrong. It should be "One hero in the animation field is Mel Blanc, the voice behind many cartoon characters." because the information after Mel Blanc is not necessary to the sentence. It's just extra, so you need a comma.
The correct answer is C. Hope that helps :)
The first one is correct. "It is like" the best decision you can ever make.
Saying it that way, is the same as saying that it would be the best decision that you can ever make, but adding more to it. Almost as if soeaking to someone who is overdramatic, and constantly say the word like.
I hope this helps