Which of the following items can enter and exit an isolated system?

Neither energy nor matter can enter and exit an isolated system.

Explanation:

There are three types of systems which refers to universe. They are

1. Open System : In an open system, both energy and matter have external interactions. Example: - boiling water in an open pan.

2. Closed system : In a closed system, only energy has interaction with surroundings. Example: - boiling water with a lid on the pan.

3. Isolated system : In an isolated system, neither energy-nor matter has external interactions with surroundings. Example : a thermos flask does not exchange energy and matter.

Hence, the correct option is (a) " neither energy nor matter ".