Which of the following matrix are singular?

• A. \(\begin{bmatrix}31&12\\26&8\end{bmatrix}\)
• B. \(\begin{bmatrix}1&11\\2&8\end{bmatrix}\)
• C. \(\begin{bmatrix}13&12\\22&8\end{bmatrix}\)
• D. \(\begin{bmatrix}3&12\\2&8\end{bmatrix}\)