Find $| B |$ ​ $B = \left[ \begin{array} { c c } 5 & 0 \\0 & - 4\end{array} \right]$

Multiple Choice

Find $| B |$ .​ $B = \left[ \begin{array} { c c } 5 & 0 \\0 & - 4\end{array} \right]$ ​

A) -19
B) -21
C) -22
D) -20
E) -18