A One-To-One Correspondence Between the Set of Counting Numbers and the Given

Multiple Choice

A one-to-one correspondence between the set of counting numbers and the given set has been established. Find an expression for the nth term of the given set that corresponds to the counting number n.
-

A) $2 n - 1$
B) $2 n + 1$
C) $2 n$
D) $2 ^ { n }$