Question: Why do areas in the middle of a large continent generally have more extreme differences in temperature than areas near the coastline?

  Options: 
 A. There are generally more clouds near the oceans.
 B. Landlocked areas are usually at a lower altitude than coastline areas.
 C. Coastlines are usually surrounded by mountains that block air masses.
 D. Oceans change temperature slowly and regulate the temperature of nearby land. 
Answer: D