Which combination of the following statements is correct ?
The incorporation of reheater in a steam power plant:
P : always increases the thermal efficiency of the plant.
Q : always increases the dryness fraction of steam at condenser inlet
R : always increases the mean temperature of heat addition.
S : always increases the specific work output.
(A) P and S
(B) Q and S
(C) P, R and S
(D) P, Q, R and S