Why scientists investigating the lives of prehistoric peoples face special challenges?

Because evolution and genetics are unable to explain cultural and social variations.

Explanation: Scientists had issues concerning identity, race and class accompanied by the lives of pre historical people. This idea emerged gradually between the sixteenth and nineteenth centuries, but came to prominence through debates about evolution in the middle of the nineteenth century. Evolution and genetics are unable to explain cultural and social variations, and this is where the study of prehistory comes in. In some cases, the methods used to investigate prehistoric sites reveal more about people's lives and habits than recorded accounts.

c) they were beaten and fired from their jobs.

a and b!

dfroos means which is a and b