The diagram above represents a chain of volcanic islands that are formed in a similar way as the Hawaiian Islands. What forms an island chain such as this?

a)The islands form slowly as the oceanic plate moves over a hotspot in the mantle.

b)The islands form from the movement of the oceanic plate underneath a land plate.

c)The islands form as the oceanic plate moves too quickly away from another ocean plate.

d)The islands form as a hotspot in the mantle moves underneath the oceanic plate.

supercell thunderstorms are perhaps the most violent of all thunderstorm types, and are capable of producing damaging winds, large hail, and weak-to-violent tornadoes

answer and explanation;

volcanic rocks are igneous rocks which form from lava, molten rock which has been thrust out of a volcano onto the surface of a rocky body such as an asteroid, planet, or dwarf planet.  

plutonic rocks are igneous rocks which form from subterranean chambers of molten rock or magma. plutonic rocks make up the base of continental crust as well as oceanic crust. their slow rate of formation causes them to be coarse grained since there is plenty of time for large crystals to form before the magma solidifies into rock.

the textural difference is that plutonic rocks are more coarse grained than volcanic rocks. plutonic rocks are coarse grained while volcanic are fine grained ; glassey or fragmental. since fine and coarse are adjectives the decision as to whether a rock is fine or coarse grained is generally made on the bases of whether or not the individual crystals can be seen in most if the rock.