According to social learning theory, an aggressive response:

A) does not require a direct reinforcer in order to be learned.
B) is delivered in the form of a shock, as in Milgram's study.
C) is common among macho types.
D) All of the above

Social learning theory, proposed by Albert Bandura, suggests that behaviors, including aggressive responses, can be learned through observation and imitation of others, without the need for direct reinforcement. This contrasts with traditional behaviorist views that emphasize direct reinforcement. Choices B and C are not directly related to the principles of social learning theory.