Why do geologists believe that part of the african continent will break off in the next 50 million years?
a. it has active volcanoes
b. it experiences severe earthquakes
c. it is near a mid-ocean ridge
d. it is part of a rift valley

D. it is part of a rift valley

Explanation:

Africa is believed to split in the future. There is still no consensus about how much will be needed for that, but it varies anywhere from 10 million years to 50 million years. There are several evidence that suggest to the geologists that this is happening, with the biggest one being the rift valley across the eastern portion of Africa.

The rift valley in Africa is actually a divergent boundary between the Nubian and Somali tectonic plates. The Somali plate moves eastward toward the Indian Ocean, thus separating itself from the larger Nubian plate.

The gap is becoming larger and larger every year, though for full separation of these two plates several millions of years will need to pass. Once the gap becomes wide enough and deep enough, the ocean water will fill it, thus making a natural barrier between the two plates, and thus creating a new separate continent.

brave new world, aldous huxley (1932)