Read the paragraph from the section "Phenomenon." The Great Lakes are a constant source of moisture. During winter months, they cause localized heavy snowfall events. This phenomenon is known as lake effect snow.

Why did the author use the word "phenomenon"?

a. to show that this level of precipitation is unique to the region
b. to highlight that heavy snowfalls are common in many areas
c. to suggest that the weather in this region is dangerous
d. to explain how this weather pattern has changed over time