The pair of lines represented by $3ax^2+5xy+(a^2-2)y^2=0$ are perpendicular to each other for

Question

$\begin{array}{1 1}(A)\;\text{two value of a}\\(B)\;\forall a\\(C)\;\text{for one value of a}\\(D)\;\text{for no values of a} \end{array}$