Volume of a given mass of the ideal gas under the constant pressure is

A. proportional to the temperature in K
B. proportional to the temperature in C
C. reverse proportional to the temperature in K
D. reverse proportional to the temperature in C

A. proportional to the temperature in K

Ideal gas equation, PV = nRT; R is constant and t is in Kelvin
In this case P and n= W/M is constant , [since constant pressure and certain given mass]

So, V proportional to T in kelvin scale (K)

For this, you just need to look at ideal gas law:
PV = nRT

Since this equation is written in SI units, temperature has a unit of Kelvins instead of Celcius. So the correct answer should be A. proportional to the termperature in K.