Match the cast irons with applications.

P. Grey cast iron	1. S.G iron pipes
Q. White cast iron	2. Chemical processing equipments requiring high corrosion, erosion and heat resistance
R. Nodular cast iron	3. Bases or beds of industrial equipments
S. Ni resist cast iron	4. Manufacture of malleable cast iron

A. P-3, Q-4, R-1, S-2

B. P-3, Q-4, R-2, S-1

C. P-4, Q-3, R-2, S-1

D. P-1, Q-2, R-4, S-3

Answer: Option A