Heat and Work are

Options

A. extensive variables
B. intensive variables
C. path functions
D. point functions

Answer

To solve the question regarding Heat and Work, we need to understand their classifications in thermodynamics.

### Step-by-Step Solution:

1. **Definition of Extensive Variables**:
- Extensive variables are properties that depend on the amount of matter present in a system. Examples include volume, mass, and enthalpy.

2. **Understanding Work in Thermodynamics**:
- In a thermodynamic process, the work done by or on a system can be represented graphically on a Pressure-Volume (P-V) diagram. The area under the curve in this diagram represents the work done.

3. **Path Dependence of Work**:
- The work done in a thermodynamic process depends on the path taken between two states. For instance, if you move from state 2 to state 3 and then back from state 3 to state 2, the work done in each direction will differ. This indicates that work is a path function.

4. **Definition of Point Functions**:
- Point functions are properties that depend only on the state of the system and not on how the system reached that state. Examples include internal energy and temperature.

5. **Heat as a Path Function**:
- Similar to work, heat transfer also depends on the path taken during a process. Therefore, heat is also classified as a path function.

6. **Conclusion**:
- Both heat and work are path functions, meaning their values depend on the specific process taken to change the state of the system.

### Final Answer:
Heat and Work are path functions.