"c' is correct . Concerning here means 'about'
<span>Watching those who are
in love. The monster feels a sense of
joy when he sees two people who are happy to be with each other. It is quite
possible that he longs for that kind of acceptance which is difficult for him
because people are afraid of him when they see him.</span>
I think it’s “who” , or “whom” because the others are genders.
A mighty, unabated
its the only answer choice with 2 adjectives