The distance between plates of a parallel plate capacitor is 'd'. Another thick metal plate of thickness d/2 and area same as that of plates is so placed between the plates, that it does not touch the plates. The capacity of the resultant capacitor :
(A) remain same
(B) becomes double
(C) becomes half
(D) becomes one fourth
(A) remain same
(B) becomes double
(C) becomes half
(D) becomes one fourth