Answer:
a)-True
Step-by-step explanation:
Isolated systems are the systems in which there is no exchange of energy as well as matter with the surroundings.
For example, a soup in an insulated container. The container acts as a isolated system as there will be exchange of heat and matter to the surroundings.
Thus, there is no exchange of energy which means that the energy of the system is constant.
The given statement is true.