(a) Metamorphic
(b) Plutonic
(c) Sedimentary
(d) Volcanic
Ans :- (b) Plutonic

Explanation :-
Plutonic rock : It is formed cooling of magma at considerable depth. It is also called intrusive Igneous rock.
Exp. Granite.
Volcanic rock : It is formed as result of solidification of molten mass laying above the earth surface.
Exp. Basalt trap.
Basalt and trap are used in road construction.