The answer to your question is d :)
Answer: P wave
Explanation: The first kind of body wave is the P wave or primary wave. This is the fastest kind of seismic wave, and, consequently, the first to ‘arrive’ at a seismic station. The P wave can move through solid rock and fluids, like water or the liquid layers of the earth.
Explanation:
Wien’s Law:

The law states that the wavelength at which black body emits maximum heat is inversely proportional to the temperature of the body in Kelvins.

1) Walls at 300 K


2) Ice water at 273 K :


3) Hot water at 373 K :


4)Skin at 310 K:


5)An incandescent light bulb at 3000 K


I believe he/she means to explain or clarify it more maybe I’m not too sure maybe talk to him/her about it