Answer: Decreased kinetic energy of the molecules
The first option that is given in the question is the correct option.
Step-by-step explanation:
The molecules of a substance act differently at different temperatures but we know that its energy is dependent on the temperature at which it is present. The normal tendency of molecules is to vibrate on move around but, when it absorbs a certain amount of heat it gains more energy and tends to move around faster.
And just the other way round happens when heat is lost so we can say with a decrease in temperature the activity of molecules will also decrease and hence the kinetic energy will be decreased.