A rigid vessel in a laboratory contains a sample of argon gas (a monatomic ideal gas of molar mass $M$). The gas has pressure $p$, volume $V$, temperature $T$, and total mass $m$. The molar gas constant is $R$.

Assuming the molar mass $M$ of argon and the gas constant $R$ are known constants, which of the following combinations of measurements is/are sufficient on its/their own to determine the total internal energy of the argon gas?

I. $p$ and $V$ II. $m$ and $T$ III. $p$ and $T$