The correct option is A True
We have to state whether the statement "If n is the number of elements of a set, the number of proper subsets is 2n−1" is True or False.
We know that, if a set has n elements then the total number of subsets is 2n including empty set and original set.
A proper subset of a set A is a subset of A that is not equal to A.
Thus total number of proper subsets is 2n−1 where −1 represents the original set.
Hence, if n is the number of elements of a set, the number of proper subsets is 2n−1.
Therefore the statement is true.