Final answer:
The group that leads to humans but not to chimps and gorillas is referred to as hominins. Hominins are species that evolved after the split from the common ancestor of hominids, sharing traits like bipedalism closely related to humans.
Step-by-step explanation:
Some scientists refer to the group that leads to humans but not to chimps and gorillas as hominins. The term hominin is used to refer to those species that evolved after the split of the primate line which led to humans, designating species that are more closely related to humans than to other hominids such as chimpanzees and gorillas. This includes species like Homo sapiens, Australopithecus, Paranthropus, and Ardipithecus. Hominins share distinct characteristics including bipedal locomotion which is not commonly found among other hominids like the great apes.
The correct answer to the question is a. Hominins.