Consider If Earth Warmed Up,and More Snow Fell Because of More

Multiple Choice

Consider if Earth warmed up,and more snow fell because of more water vapour in the atmosphere,and that snow then reduced Earth's temperature,which then increased snow cover.Which of the following pairs of words best define first the initial increase in snow fall,and second,the continued increase in snow fall?

A) Positive; positive.
B) Positive; negative.
C) Negative; positive.
D) Negative; negative.