The answer you are looking for is C
Answer: C. Both of the sisters sing in the choir.
C. The man was a slippery snake, who always managed to slither out of trouble.
Reason being the definition of a metaphor is: a figure of speech containing an implied comparison, in which a word or phrase ordinarily and primarily used of one thing is applied to another.
D. Virility
Virility simply means something like manliness, it is not a system of beliefs on it's own. Instead it is a personal quality, whereas feminism, humanism and misanthropy are all separate belief systems.