2018 AMC 12A Problem 12

Let S be a set of 6 integers taken from \{1,2,\ldots,12\} with the property that if a and b are elements of S with a<b, then b is not a multiple of a. What is the least possible value of an element in S?

\textbf{(A)}\ 2\qquad\textbf{(B)}\ 3\qquad\textbf{(C)}\ 4\qquad\textbf{(D)}\ 5\qquad\textbf{(E)}\ 7

Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.