The temperature of an ideal gas increases in an:

The correct option is C Adiabatic compression
In isothermal processes the temperature of the system remains same and in an adiabatic processes heat exchange of the system and surrounding is zero. So, in adiabatic expansion, amount of work done by the system is equal to the decrease in internal energy of the system and oppositely in adiabatic compression, amount of work done on the system is equal to the increase in internal energy of the system. Since, internal energy is directly proportional to temperature, thus the temperature of an ideal gas increases in an adiabatic compression.