Explanation:

- Option 1: Mosca: Gaetano Mosca is known for his work on political theory, particularly the concept of political class, but he did not write "Who Governs?".

- Option 2: Michels: Robert Michels is famous for the "iron law of oligarchy" in political theory; however, he is not the author of "Who Governs?".

- Option 3: Dahl: Robert A. Dahl, a prominent political scientist, wrote "Who Governs?" which examines democracy and political power in America.

- Option 4: Rose: Richard Rose is a political scientist known for his work on comparative politics and public policy, not the author of "Who Governs?".