Geologists observed signs of widespread ancient glaciers from the same time period in areas across South America, Africa, Antarctica, India, and Australia What theory

did this observation support?

Those continents were once together as one supercontinent.

The continental drift theory

Explanation:

According to the continental drift theory, proposed by Alfred Wegener, the continents were once all together forming a huge super continent. This super-continent is known as the Pangaea. During the time of this super continent, episodic ice age has taken place and due to the continuous tectonic activities, the super-continent got split up into different continents. This continents still has the those structures and features such as scratch marks over the land surface at many places that have developed during the glacial movement in the super continent.

Presently, these continents have moved further away.

Thus, these observation led to the formation of the continental drift theory.