If $A=\left[\begin{array}{ccc}0& c& -b\\ -c& 0& a\\ b& -a& 0\end{array}\right]$ and $B=\left[\begin{array}{ccc}{a}^2& ab& ac\\ ab& b^2& bc\\ ac& bc& c^2\end{array}\right],$ then $AB=$

The correct option is A $O$
Given : $A=\left[\begin{array}{ccc}0& c& -b\\ -c& 0& a\\ b& -a& 0\end{array}\right]$ $B=\left[\begin{array}{ccc}{a}^2& ab& ac\\ ab& b^2& bc\\ ac& bc& c^2\end{array}\right]$

Then, $AB=\left[\begin{array}{ccc}0& c& -b\\ -c& 0& a\\ b& -a& 0\end{array}\right]\left[\begin{array}{ccc}{a}^2& ab& ac\\ ab& b^2& bc\\ ac& bc& c^2\end{array}\right]$
$=\left[\begin{array}{ccc}abc-abc& b^{2}c-b^{2}c& b{c}^2-b{c}^2\\ -a^{2}c+a^{2}c& -abc+abc& -a{c}^2+a{c}^2\\ a^{2}b-a^{2}b& a{b}^2-a{b}^2& abc-abc\end{array}\right]$

$=O$