Best example of an isolated system in chemistry apex

Answer;

Universe is a best example of isolated system.

-Also a perfectly isolated vacuum flask containing a hot or cold liquid is an example of an isolated system,

Explanation;

An isolated system is a thermodynamic system that cannot exchange either energy or matter outside the boundaries of the system. An isolated system differs from a closed system by the transfer of energy.

A system is isolated when there is no energy exchange with the surroundings. For example the contents of a vacuum flask are isolated. Because the hot or cold liquid in a flask is being closed off from its surrounding by the thermo bottle and there is no exchange in neither energy nor matter, the system is isolated.

im pretty sure its b