Mr. Martinez praises Nolan in front of the rest of the class for raising his hand and answering a discussion question correctly. The next day during class discussion, Mr. Martinez expects to see Nolan raise his hand and offer correct responses again. However, Nolan slumps in his seat, avoids eye contact, does not raise his hand to be called on, and when called on, offers no response. In regards to his class participation, praising Nolan served as


a.
negative reinforcement.
b.
positive reinforcement.
c.
presentation punishment.
d.
removal punishment.