Which explains what happens to a warm air mass at a warm front?

A.
A warm air mass overtakes a cold one, and the warm air rapidly rises and cools. The water in the air condenses to form clouds and severe thunderstorms.

B.
A warm air mass overtakes a cold one, and the warm air gradually rises and cools. The water in the air condenses to form clouds and severe thunderstorms.

C.
A warm air mass overtakes a cold one, and the warm air gradually rises and cools. The water in the air condenses to form clouds and moderate precipitation.

D.
A cold air mass overtakes a warm one, and the cold air gradually sinks and warms. The water in the air condenses to form clouds and moderate precipitation.

The warm fronts are the frontal surfaces that have a moderate slope. Here the warm and light air containing moisture becomes light and active and it eventually rises up over the dense cold air. This rising warm air then gets saturated and after condensation, they fall back in the form of moderate rainfall or snowfall. This precipitation usually takes place doe several areas over a comparatively large area. After precipitation, warmer and milder weather occurs in that area.

Hence, the correct answer is option (C).