Let $I = \left( \begin{array} { l l } 1 & 0 \\ 0 & 1 \end{array} \right)$ and $P = \left( \begin{array} { l l } 2 & 0 \\ 0 & 3 \end{array} \right)$. Let $Q = \left( \begin{array} { l l } x & y \\ z & 4 \end{array} \right)$ for some non-zero real numbers $x , y$, and $z$, for which there is a $2 \times 2$ matrix $R$ with all entries being non-zero real numbers, such that $Q R = R P$.
Then which of the following statements is (are) TRUE?
| (A) | The determinant of $Q - 2 I$ is zero |
| (B) | The determinant of $Q - 6 I$ is 12 |
| (C) | The determinant of $Q - 3 I$ is 15 |
| (D) | $y z = 2$ |