During childbirth, physical stretching of the uterus causes the release of a hormone that results in stronger, more frequent contractions. These contraction increase the stretching of the uterus. This is an example of

A) a positive feedback loop, because the hormone increases uterine stretching.

B) a negative feedback loop, because the hormone increases uterine stretching.

C) a positive feedback loop, because a condition in the body causes an increase in a hormone.

D) a negative feedback loop, because a condition in the body causes an increase in a hormone.