Which weather condition commonly occurs along a cold front

Cold fronts form when a cooler air mass moves into an area of warmer air in the wake of a developing extratropical cyclone. The warmer air interacts with the cooler air mass along the boundary, and usually produces precipitation. Cold fronts often follow a warm front or squall line.

Precipitation is your answer. according to my science textbook, in a cold front, warm air and cold air interact and cause precipitation.