Question

which of the following contributes to cold winters and hot summers in the great plains? the regular volcanic activity in the great plains region the absence of pacific winds blocked by the rocky mountains a wind - tunnel effect created by the agriculture on the plains

Explanation:

1. The Great Plains has little volcanic activity, so the first option is incorrect.
2. The Rocky Mountains block Pacific winds (like westerlies with moisture), leaving the Great Plains with more extreme temp changes (cold winters, hot summers) due to lack of moderating Pacific air.
3. Agriculture doesn’t create a “wind - tunnel effect” that drives extreme seasonal temps, so the third option is wrong.

Answer:

the absence of Pacific winds blocked by the Rocky Mountains