Thermodynamic processes are indicated in the following diagram.

Match the following:

P-c, Q-a, R-d, S-b

The correct answer is option 3. P-c, Q-a, R-d, S-b.

In the given diagram, we can understand the process I depicted constant volume which means it is an Isochoric Process.

Process III shows constant temperature which means it is an Isothermal Process.

Process IV shows constant pressure which means it is an Isobaric Process.

The only option which matches the above explanation is option C which tells that the process II is an Adiabatic Process.

Thus, Process I is Isochoric, Process II is Adiabatic, Process III is Isothermal and Process IV is Isobaric.

So, the correct answer is option 3. P-c, Q-a, R-d, S-b.