Guppies were moved from stream A, with a fish that preyed upon adult guppies, to stream B, with a fish that preyed upon juvenile guppies. After 30 to 60 generations, the guppies responded to the increased predation on juveniles relative to adults by:.
A) Feeding less frequently.
B) Increasing age at maturity.
C) Increasing the number of individuals in a school.
D) Becoming smaller in body size.