Answer:
The correct answer is - 3.66 million years ago.
Step-by-step explanation:
Laetoli, located on the Eyasi Plateau which is known for the remains or footprints of the oldest hominin that were formed and preserved by a series of events - a volcanic eruption, a rainstorm, and another ashfall.
The remains and footprints were discovered at 1978 and are attributed to Australopithecus afarensis. The age of this remaining footprint can be estimated with the help of the radiometric method of the remains which tells that the footprints are 3.66 million years ago formed.