What is lactic acid fermentation?

Which of the following is a common response to cell signaling?

The many stone tools, fragmentary animal bones, and teeth found at gran dolina, spain, indicate that hominids there? a. processed and consumed animals and other hominids. b. did not differ appreciably from earlier asian homo erectus. c. were similar to later homo sapiens. d. none of the above

Amajor source of energy for your body comes from