A shy and timid child works up the courage to raise his hand to answer a question. The teacher calls on him and the child delivers an excellent answer. The teacher exclaims, "That is the best answer I have heard all week! Great job! Come up to the front of the room to get a sticker!" Unfortunately, the child found all of this attention unpleasant and no longer answers questions in class. His behavior of answering questions was:
A. negatively punished.
B. positively punished.
C. positively reinforced.
D. negatively reinforced.