Thermodynamics Part 2

In graph (A) vertical line is isochoric process, so the graph (A) is incorrect.
In graph (B) horizontal line is isobaric process, so the graph (B) is incorrect.
In graph (C) and (D) vertical line is isothermal process and the curve line is adiabatic process.
So, the correct representation of thermodynamic process graph is (C) and (D).
So, the correct option is (b)