The correct response is:
Around that time, those regions were located in tropical climates that were partially submerged on the coasts.
This observation supports the theory of plate tectonics because it indicates that the positions of continents have changed over geological time. The formation of coal deposits typically requires warm, wet conditions, such as those found in tropical regions, where plants can grow abundantly and accumulate. The existence of large coal deposits from that period suggests that the regions where they are found today were located near the equator at that time, supporting the idea that the continents have moved due to tectonic plate activity.