A system is described in terms of thermodynamics variables:

Explanation

The correct answer is 'All of these.' In thermodynamics, a system's state is typically described by a set of variables including pressure (P), temperature (T), and volume (V), among others. Each of these variables provides different information about the system. Pressure relates to the force exerted by the system, temperature indicates the thermal energy, and volume measures the space the system occupies. Using these variables together allows for a comprehensive description of the system's state. The other options, while each representing an important thermodynamic variable, do not alone provide a complete description of a system.