Question

between 1845 and 1852, ireland endured a major famine caused by
a potato blight.
mild weather.
crop surpluses.
locust attacks.

Explanation:

The 1845-1852 Irish famine, also called the Great Famine, was triggered by a water mold (Phytophthora infestans) that caused potato blight. This destroyed the potato crop, which was the primary food source for most Irish people at the time. The other options are incorrect: mild weather, crop surpluses, and locust attacks were not the cause.

Answer:

a potato blight.