Fourteen-year-old Judy Ann is frustrated with the way the kids at school treat her during lunch. Instead of sitting by herself like she normally does, she sits with another student at lunch. As they begin to engage in conversation, she notices that no one stops to make fun of her. Because of this, she decides to no longer sit by herself at lunch. What can be considered the reinforcer?

No one making fun of her

Explanation:

Operant conditioning is method of learning. it involves the use of reward and punishment for a particular behavior.

A Reinforcer is that particular action that increase the rate of occurrence of a particular behavior.  there are positive and negative reinforcer.

Judy Ann due to the Positive reinforcer that no one is making fun of her after she included herself sitting with other student,  She will want to sit more with other student so that no one will make fun of her

answer; i believe the correct answer is (4) flip a coin as each participant arrives,heads indicates assignment to the first group: tails indicates assignment to the second group;