If A={3,6,9,12,15,18,21},B={4,8,12,16,20},C={2,4,6,8,10,12,14,16},D={5,10,15,20} (vi) D-A

Question

$\begin{array}{1 1}(A)\;\{5,10,15,20\}&(B)\;\{3,6,9,12,15,18,21\}\\(C)\;\{3,6,9,12,18,21\}&(D)\;\{5,10,20\}\end{array} $