Melvin's Parents Have Been Ignoring His Crying When He Is

Multiple Choice

Melvin's parents have been ignoring his crying when he is put to bed. Melvin has gone five nights without crying. However, on the sixth night he begins to cry when put to bed. What principle may be responsible for Melvin's crying reappearing?

A) forgetting
B) differential reinforcement
C) spontaneous recovery
D) ratio strain
E) ordinal proximity