A thermodynamic process in which temperature $T$ of the system remains constant though other variables $P$ and $V$ may change, is called
A. Isochoric Process
B. Isothermal Process
C. Isobaric Process
D. None of these

Hint:
In the case, when a problem is based on thermodynamics, we know that all the parameters such as pressure, temperature, volume, work done, etc., vary with the given conditions of the system and surroundings hence, use different processes given in thermodynamics to state the answer for the given situation.



Complete step by step solution:
Let us consider all the four options given one by one: -
Isochoric Process in thermodynamics is a process during which the volume $V$ of a system remains constant whereas other variables $P$ and $T$ may change that’s why it is also referred to as a constant-volume process.
Isothermal Process in thermodynamics is a process during which the temperature $T$ of a system remains constant whereas other variables $P$ and $V$ may change that’s why it is also referred to as a constant-temperature process.
i.e., In Isothermal process, $\,Change{\text{ }}in{\text{ }}Temperature = \Delta T = 0$
Isobaric Process in thermodynamics is a process during which the pressure $P$ of a system remains constant whereas other variables $V$ and $T$ may change that’s why it is also referred to as a constant-pressure process.
Graphically, an isothermal process can be represented as: -

Thus, in thermodynamics, the temperature remains constant in the Isothermal Process.
Hence, the correct option is (B) Isothermal Process.






Note:
In this problem, to determine the exact thermodynamic process for the given situation we must know the basic fundamentals and definition of all processes given in the options to give a correct answer such as: -
In Isobaric process, $\Delta P = 0$
In Isothermal process, $\Delta T = 0$
In Isochoric process, $\Delta V = 0$