Morbid and Cheerful
Virulence and Mildness
Propagate and Discourage
I'm assuming these should be right from what I've learned from a thesaurus. Hope this helps.
The answer C correctly uses possessive form and is the right answer. It's not A because there is only one George so the apostrophe is in the wrong place. In B, there's not even an apostrophe and it's not clear as to whether there is only one cousin or two or more cousins. In answer D, here should not be an apostrophe for develops.
A explaining the benifits of following the viewpoints
Because juliet is living on another side
If you are critical of someone or something, you show that you disapprove of them.