The choices are:
A. The first gas sample has a temperature of 273 K, and the second gas sample has a temperature of 0°C.
B. The first gas sample has a temperature of 273 K, and the second gas sample has a temperature of 298 K.
C. The first gas sample has a temperature of 273 K, and the second gas sample has a temperature of 273° C.
D. The first gas sample has a temperature of 273 K, and the second gas sample has a temperature of 100° C.
The correct answer is A because the two gases will have the same temperature and 273 K = 0°C