Erikson's young adulthood stage occur between ages __________

A cross-sequential design:

examines a single group of people who are the same age at one point in time. examines two or more groups of people who are of different ages at one point in time. follows a single group of people over an extended period of time. follows two or more groups of people who are of different ages over a period of time.

The abbreviation UCR stands for _____

A) unconditional reinforcement B) uniform conditioned rule C) unconditioned response D) unconventional response