Question

what does it mean for a set to be \closed\? (1 point)
an expression belonging to a closed set cannot be used to create an expression that is not of that set.
members of a closed set cannot be added, subtracted, multiplied, or divided.
an operation performed on members of that set will result in a member of the same set.
the set has a finite number of members, as opposed to being infinitely large.

Explanation:

In mathematics, a set is closed under an operation if performing that operation on elements of the set always yields an element of the same set. For example, the set of integers is closed under addition because adding two integers always results in an integer.

Answer:

An operation performed on members of that set will result in a member of the same set.