Answer:
D. Large oceans
Step-by-step explanation:
During the Carboniferous period, the majority of the land masses were merged into one large supercontinent, with smaller landmasses being very close to it. This meant that there was one enormous ocean surrounding the supercontinent, but also one smaller one that was getting deeper into the land masses. The large Panthalassic Ocean had huge effect on the climate on Earth in this period. Because it was so large, it produced very large air masses, mostly warm and wet, causing a lot of precipitation, resulting in warm and wet climate in most of the planet. It was also an ocean that was capable of producing storms and waves much larger than anything we can see nowadays, managing to cause lot of damage along the coastlines of the supercontinent.