Answer:
Cold front
Explanation:
A cold front forms when a cold air mass pushes under a warmer air mass and forces the warm air to rise.
B is wrong. An occluded front is formed when a cold front overtakes a warm front.
C is wrong. a warm front forms when a warm mass replaces a colder air mass.
D is wrong. A stationary front is a cold or a warm front that has stopped moving.
