The correct answer is: D. The ocean moderates air temperatures.
Coastal areas tend to have milder climates compared to inland regions because the ocean acts as a temperature buffer. During the summer, the ocean absorbs heat and keeps coastal areas cooler, while in the winter, the ocean releases stored warmth, which helps to keep coastal areas warmer than those further inland. This moderating effect leads to cooler summers and warmer winters in coastal regions compared to their inland counterparts at the same latitude.