ANS:B - 0°K

Cp equals Cv at 0°K, which corresponds to absolute zero temperature. In thermodynamics, Cp and Cv represent specific heat capacities at constant pressure and constant volume, respectively. At absolute zero temperature (0 Kelvin or -273.15°C), the kinetic energy of particles is minimal, and the motion of particles ceases. At this temperature, gases behave ideally, and there is no thermal energy associated with the motion of particles. Therefore, at absolute zero temperature, the internal energy of the gas is solely determined by the translational motion of particles, and it is independent of the volume. As a result, at absolute zero temperature, the specific heat capacities at constant pressure (Cp) and constant volume (Cv) become equal, and Cp equals Cv. So, Cp equals Cv at 0°K.