Suppose Earth Were to Cool Down a Little

Suppose Earth were to cool down a little.How would the carbon dioxide cycle tend to restore temperatures to normal?

A) Cooler temperatures cause volcanoes to become more active,so they release more carbon dioxide into the atmosphere than they do when temperatures are warmer.
B) Cooler temperatures allow carbon dioxide to form rain and rain out of the atmosphere.
C) Cooler temperatures mean more ice and more erosion,which somehow makes the planet warm up.
D) Cooler temperatures lead to slower formation of carbonate minerals in the ocean,so carbon dioxide released by volcanism builds up in the atmosphere and strengthens the greenhouse effect.