What Was Significant About the Laetoli Site in Tanzania?​

What was significant about the Laetoli site in Tanzania?​

A) ​It was where the earliest human ancestors were found 7 million years ago.
B) ​It was the site where the earliest biped was excavated in 1978.
C) ​It was the site where volcanic ash preserved the remains of 36 human beings.
D) ​It was the site where foot impressions of a biped were preserved from 3.6 million years ago.