What Is the Primary Reason That Aurorae Are More Likely

What is the primary reason that aurorae are more likely to be seen in Canada and Alaska than in Iowa?

A) The particles that produce aurorae strike the atmosphere only near the poles
B) There are fewer hours of nighttime each year in Iowa than in Canada
C) Aurorae can only be seen above the Arctic Circle
D) Aurorae are sunlight reflected from snow,which is more common in Canada