Final answer:
Primates, including monkeys, apes, and humans, have forward-looking eyes as an adaptation for hunting small prey in the forest undergrowth. They also have larger brains and eyes and a reduced snout, relying more on vision than smell. The correct option is 3.
Step-by-step explanation:
Forward-looking eyes are a characteristic of primates, which include monkeys, apes, and humans. Primate features, such as forward-facing eyes, grasping hands and feet, the presence of nails instead of claws, and stereoscopic vision, have evolved as adaptations to hunting insects and other small prey in the forest undergrowth.
Primates also have larger brains, larger eyes, and a reduced snout, relying more on their sense of vision and less on their sense of smell compared to other mammals. Hence, 3 is the correct option.