# The process in which heat is neither allowed to enter nor allowed to leave the system but in which temperature changes in known as

$(a)\;\text{Adiabatic} \\(b)\;\text{Isochloric} \\(c)\;\text{Isobaric} \\(d)\;\text{Isothermal}$

The process in which heat is neither allowed to enter nor allowed to leave the system but in which temperature changes in known as Adiabatic
Hence a is the correct answer.