Answer:
The correct answer is - all of the above.
Step-by-step explanation:
If the cold and warm front collide the warmer air rises and colder air moves to the bottom due to the density of warm air is less than cold air which creates a front that is the boundary front of both fronts.
It forms a new front called an occluded front. The occluded front causes heavy precipitation, strong winds. and snow sometimes. In low pressures it also caused tornadoes.