Which statements is/are true for an adiabatic throttling (Joule-Thomson) expansion?
(A)
The process is isenthalpic (enthalpy $H$ is conserved)
(B)
The Joule-Thomson coefficient is $\mu_{JT} = \left(\frac{\partial T}{\partial P}\right)_H$
(C)
For an ideal gas, $\mu_{JT} = 0$ identically
(D)
A real gas always cools upon expansion regardless of temperature