Mid-ocean ridges, such as the mid-Atlantic ridge, normally form when tectonic plates are:
1) converging
2) diverging
3) stationary
4) sliding past each other

mid ocean ridges are formed when the two plates are pulled apart, due to the power of the convection current. lava flows through this newly formed gap and reacts with the water above, forming rock. Leaving an underwater mountain range (the answer is b, sorry for a late response!) 

Explanation:

a supercell is a thunderstorm with a deep, persistently rotating updraft. supercells are the least common form of thunderstorm yet they are potentially the most violent. large hail of greater than baseball size, strong damaging winds, and tornadoes can accompany these storms.

explanation: