The given diagram shows four processes i.e., isochoric, isobaric, isothermal and adiabatic. The correct assignment of the processes, in the same order is given by:

• A

  $\mathrm{a}\mathrm{ }\mathrm{d}\mathrm{ }\mathrm{b}\mathrm{ }\mathrm{c}$
• Correct answer
  B

  $\mathrm{d}\mathrm{ }\mathrm{a}\mathrm{ }\mathrm{b}\mathrm{ }\mathrm{c}$
• C

  $\mathrm{a}\mathrm{ }\mathrm{d}\mathrm{ }\mathrm{c}\mathrm{ }\mathrm{b}$
• D

  $\mathrm{d}\mathrm{ }\mathrm{a}\mathrm{ }\mathrm{c}\mathrm{ }\mathrm{b}$

Hence, the correct answer is option: 'B'.