B.) Reference Group
<em>A reference group is the group of people that a person looks to as a point of comparison</em>. This is in terms of attitude, looks, behavior, skill, etc.
In Marina's case, she looks up to the two singers and uses them as a reference point in terms of her singing skill and style, as well as her behavior. In doing this, they become her <em>reference group</em>.
Answer:
Your answer here is gonna be C.
Explanation: I'm really bad at explaining, but have an amazing day :D