$\begin{array}{1 1} \text{(a) P: potential energy,
V: velocity,
n: moles,
R: ideal gas constant
T: total energy} \\ \text{(b)P: pressure,
V: volume,
n: moles,
R: ideal gas constant,
T: temperature,} \\ \text{(c)P: pressure
V: volume
n: moles
R: rate
T: time} \\ \text{(d) P: pressure,
V: volume,
n: moles,
R: ideal gas constant,
T: time}
\end{array} $
