Let N be the set of natural numbers and P be the set of prime integers in N.If $A=\{n/n\in N,n$ is a multiple of some prime $P\in P$,then $N-A=\{n\in N/n\in A\}$ is

Question

$\begin{array}{1 1}\text{empty set}\\\text{of cardinality 2}\\\text{a finite set of cardinality greater than 2}\\\text{a singlet on set}\end{array} $