Need for is the attraction toward those with qualities we admire but lack, and need for is the attraction based on sharing similar needs.

Need for "complementarity" is the attraction toward those with qualities we admire but lack, and need for "compatibility" is the attraction based on sharing similar needs.

The suggestion that individuals have a tendency to be pulled in to other people who have complementary needs to their own, a man with a high requirement for predominance, for instance, being pulled in to a man with a high requirement for accommodation, and the other way around Compatibility does not rely on some individual stock of characteristics. Similarity isn't something you have. It's something you make. 

The answer should be a.