If A is a square matrix of order 3, $B = kA$ and $B = x |A|$ then,

$x=2k$ $x=k^2$ $x=k^3$ $x=3k$

$x=k^3$

$A$ → order (3 × 3) $B = |kA|$ So, $|B|=|kA| = k^3|A|$  (as A has order 3) $x=k^3$  (upon comparing)