Which of the following correctly describes the general trend in the evolution of hominid teeth? a: molars have become larger and flatter as the hominid diet became more reliant on plant materials. b: canines have increased in size as hominids developed more effective hunting techniques. c: tooth size has decreased as hominids evolved toward the use of tools. d: tooth size has increased as the hominid evolved toward a larger brain cavity and skull.

The correct answer will be option C.

Explanation:

By studying the fossils it has been suggested that human teeth like other bones also evolved with time. These teeth evolved in humans as the food diet of the ancestors changed from eating plants to hunting and eating the meat of other animals.

Human teeth size has generally decreased in size during evolution which is easily observed in the molar teeth or wisdom teeth.  In modern human or Homo sapiens, the wisdom teeth are usually smaller as compared to ancient hominins like Paranthropus boisei or “Nutcracker” that lived 2.3 million years ago with the largest molars. This change developed due to use of the advanced tool by the genus Homo as with the use of tools humans did not have to spend much energy on developing teeth.

Thus, option C is the correct answer.