Over millions of years, hominid species learned to use and create tools that became more complex over time. they eventually shaped stone into knives used for cutting, and they harnessed fire for light, heat, and cooking food. which of the following best explains what effect this had on hominid evolution?

a. hominid brain size decreased as life became easier with the advent of tools.
b. hominid hands developed smaller thumbs as they developed finer tools.
c. hominid tooth size decreased as they relied on cooked foods and tools for cutting.
d. hominid front limbs became longer in proportion to the rest of their body.