What Is the Significance of the Footprints Found at Laetoli

What is the significance of the footprints found at Laetoli?

A) The Laetoli footprints indicate that upright hominins entered the world stage approximately 4,000,000 years ago.
B) The Laetoli footprints indicate that hominin species formed complex societies as long as 4,000,000 years ago.
C) The Laetoli footprints tell us that early hominins were capable of forging simple tools from stone.
D) The Laetoli footprints tell us that early hominins used visual symbols to communicate with one another.