The weather map shown in the image forecasts the weather over a region. What causes the weather conditions shown in the map?

A)
a warm air mass being pushed away by a colder air mass, resulting in a cold front


B)
a warm air mass pushing a cold air mass out of its way, resulting in a warm front


C)
a cold air mass rapidly overtaking a warm air mass, resulting in an occluded front


D)
a cold air mass meeting a warm air mass, forming a stationary front over the region