The correct answer is B, a social class. 'Interest groups' have the same interest that influences them. "A political party' is about politics. And D isn't correct as this is not a culture, it is merely a class.
A school of anchovies or a gaggle of geese or even a pod of orca whales would be a population. A population refers to all members of the same species.
The passage of red riding hood illustrates the storytelling element of exposition.
