Review the passage:
Whenever Coach Moody sees behavior that she does not like—either on
or off the court. The members of the girls' basketball team pay during
the next practice. When Frankie was caught smooching
her boyfriend Larry in the hallway, everyone had to run two extra miles
that afternoon.
You chose the third part, When Frankie was caught smooching her boyfriend Larry in the hallway, everyone had to run .... This part has a main clause: everyone is the subject; had is the verb. A fragment will not have a main clause.