You Are Passing Through One of the Science Buildings on a University

You are passing through one of the science buildings on a university campus when you see a researcher come out of his laboratory and go into another room.You hear and then see a newly hatched duckling come out of the lab and run to follow the researcher into the other room.The duck's behavior can best be described as

A) a fixed action pattern.
B) classical conditioning.
C) imprinting.
D) operant conditioning.
E) altruistic.