The earliest mammals
A) were active during the day.
B) were large organisms.
C) dined on insects.
D) had a poor sense of hearing.
E) has superb visual systems.

Question

Quizplus · Accepted Answer

The earliest mammals are believed to have lived during the time of the dinosaurs, and they were small, nocturnal insectivores. Therefore, they dined on insects.

Answer: A
 The earliest mammals were small, nocturnal insectivores, which means they were active during the night when insects were more abundant. However, as daytime predators (dinosaurs) became more prevalent, some mammals began to shift their activity patterns and become active during the day to avoid competition and predation.

Therefore, choices B, D, and E are incorrect.

The Earliest Mammals