What is the difference between air tempertature and dewpoint when the air is dry

The Dew Point temperature is always lower than the Dry Bulb temperature and will be identical with 100% relative humidity (the air is at the saturation line). As air temperature changes the Dew Point tends to remain constant unless water is added or removed from the air.

Explanation:

the answer to your question is c

while cooking a piece of 1/2 pound beef steak, a cast iron pan (2.4kg in weight) was heated 260 celsius.