Match the following:

Group 1	Group 2
P. Dulong formula	1. Ultimate analysis
Q. Carbon	2. Gray body
R. Dwight-Lloyd machine	3. Sintering
S. Radiation	4. Refractory

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

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

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

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

Answer: Option C