Answer:
A. The continents were pushed apart when new crust formed in the center of the ocean and pushed older crust away from the volcanic ridges.
Step-by-step explanation:
The crust is divided into many plates that move over the mantle. Nowadays, there are six different bigger plates and twelve that are smaller. These plates are limited by three types of ridges or borders that differ in the movement they produce.
Boundaries types:
I. Divergent
II. Convergent
III. Transforming
In divergent boundaries, a new crust is created by the rising molten materials coming from the mantle. Two plates separate, and the stream of hot material creates a new seabed between them. It occurs an expansion of the sea bottom. As old plates get separated, the new and young crust instantaneously gets formed. The emerging mantle occupies the space left by the separation of the two plates. This process occurs along with an underwater mountain range, known as the mid-oceanic ridge or divergent ridge. An example of this is the ridge located in the middle of the Atlantic Ocean, extending from Greenlander to the southernmost point of South America.