D
Below is a question with multiple-choice answers. Choose the correct option based on your reasoning.

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

### Choices:
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:
