Question

multiple choice question
a system is anything around which you can imagine a
o group of objects
boundary
o change in energy
o vacuum

Explanation:

In thermodynamics, a system is defined as a region or quantity of matter that is separated from its surroundings by a boundary. This boundary can be real or imaginary. A group of objects does not define a system as precisely as a boundary. A change in energy is a characteristic of processes within or involving a system, not what defines the system itself. A vacuum is a specific type of environment (lack of matter) and not what defines a general system.

Answer:

boundary