(A) This statement is true for an ideal gas. The internal energy of an ideal gas depends only on temperature, and for an ideal gas, \( \frac{\partial U}{\partial T}_V =0 \) since the energy is a function of temperature alone and not of volume.
(B) This is incorrect because \(\frac{\partial U}{\partial T}_V =0\) for an ideal gas, meaning the internal energy does not increase with temperature for constant volume.
(C) This is correct. The pressure of an ideal gas increases with temperature at constant volume, so \(\frac{\partial P}{\partial T}_V > 0\).
(D) This is incorrect. The volume of an ideal gas depends inversely on pressure for a given temperature, so \( \frac{\partial V}{\partial P}_T < 0 \).