A body has the following combinations of acceleration, position and velocity at one instant. Which of the following combinations describes $SHM$:

Question

$\begin{array}{1 1}(a)\;6,3.5,3 \\(b)\;5,4,1 \\( c)\; 7,3,2 \\(d)\; none\;of\;the\;above \end{array}$