Answer:
It would be choice: C
Step-by-step explanation:
The reason for this is that major volcanic activity didn't have much to do with pangaea from what I have learned, therefore, choice A isn't the answer. Like last answer magma rising up to the crust had nothing to do with panaea AND if magma were to rise up, all the land would be burned by lava. Lastly choice D, the Earth's crust colliding together and causing earthquakes would make the land drift away but would start cracking it, however it wouldn't be enough to make the land drift away unless earthquakes happened 24/7. That leaves us with C as our final and only reasonable choice. :)
Hope this helped!
Sorry the explanation is long.