Final answer:
According to Singh and his colleagues (2000), dissimilar attitudes depress liking more than similar attitudes enhance liking.
Step-by-step explanation:
In the context of similarity versus complementarity, according to research conclusions reached by Singh and his colleagues (2000), the true statement is B. Dissimilar attitudes depress liking more than similar attitudes enhance liking.
This means that people tend to like others who have similar attitudes or beliefs rather than those with different attitudes. When someone's attitudes are similar to our own, it can enhance our liking for them. On the other hand, if someone has dissimilar attitudes, it can have a negative effect on our liking for them.
For example, if you and a friend have similar attitudes about environmental issues, it may strengthen your friendship. However, if you have opposing attitudes, it may create tension and decrease your liking for each other.