Degrees of freedom and specific heats of gases

2024 Re-NEET 1 question

1. According to the law of equipartition of energy, the number of vibrational modes of a polyatomic gas of constant $\gamma=\dfrac{C_p}{C_v}$ is ($C_p$, $C_v$ are the specific heat capacities of the gas at constant pressure and constant volume, respectively):