Why Do Higher-Latitude Ecosystems Experience More Pronounced Seasons Than Ecosystems

Why do higher-latitude ecosystems experience more pronounced seasons than ecosystems at equatorial latitudes?

A) Air currents generated by Earth's rotation have stronger effects at higher latitudes.
B) Heated air rises at the equator and falls at mid-latitudes.
C) Earth is tilted on its axis as it orbits the sun annually.
D) The mass of the continents is greater at the equator, which evens out temperature variations in ocean circulation.
E) Ocean currents moderate near-shore environments.