Answer:
the average kinetic energy of water particles - C.
Look at the third one i think its the answer
Your answer would be total number of atoms! This is because when you have these equations which require total number of atoms.
Answer:

Explanation:
As we know that the speed of the sound is given as

now at t = 273 k = 0 degree

so we have


now when temperature is changed to 313 K we have

now we have



now from two equations we have

so we have


The answer to question one is A.
The answer to question two is A.
The answer to question three is D.