The correct answer to the question is : By increasing the pressure.
EXPLANATION:
Before answering this question, first we have to understand Gay lussac's law.
As per Gay lussac's law, the pressure of a gas increases or decreases by 1/273 th of its pressure at zero degree celsius; for every 1 degree celsius rise or fall of temperature at constant volume
In a simple way, the pressure is directly proportional to absolute temperature.
Mathematically P ∝ T. [ P = pressure and T = temperature]
Hence, increase in pressure at constant volume may increase its temperature.
