Answer: It would be D, "People have greater access to individuals like themselves".
Explanation: Because people with the same culture share the same vision of life, the same social identity, habits and customs that includes marital matters, and in this frame is common that people of the same group tend to chose individuals similar to their own.
In this sense, we may define culture such as the set of knowledge, ideas, traditions and customs that characterize people or a social group.