Match the following components to their material.

P. Bush bearings	1. Tungsten-silver
Q. Incandescent lamp filaments	2. Copper-tin
R. Cutting tools	3. Thoria doped tungsten
S. Heavy duty electrical contacts	4. Tungsten carbide-13% cobalt

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

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

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

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

Answer: Option A