Answer:
people of similar age, who share similar interests
Neither, a metaphor would be like "I'm so hungry that I could probably eat an elephant," while a simile would have 'like' or 'as' to describe something.
The question ask to choose among the following choices that best answer that could fit and support the statement in your question, and based on my further analysis about it, I came up with an answer of letter D. Substance. I hope you are satisfied with my answer and feel free to ask for more
