Which of these persuasive techniques takes advantage of people's desire to conform?

Bandwagon

Explanation:

Bandwagon is a persuasion technique that carried out by using popular trend to influence other people's behavior.

Example of this would be when people start hating a certain political candidate without actually knowing the policies made by that candidate. They only do it majority of the people they know start hating that candidate to.

This happen because People are naturally a social being. If the majority of people in their social group start adopting a certain opinion, they will experience some sort of pressure to conform to the same opinion due to the fear of being an outcast.