Where l and m are direct cosines, then transformation matrix L is given by ___

• A. \(\begin{bmatrix}l & 0 \\ m & 0\\0 & l\\0 & m \end{bmatrix}\)
• B. \(\begin{bmatrix}l & 0 \\0 & m \end{bmatrix}\)
• C. \(\begin{bmatrix}l & m \end{bmatrix}\)
• D. \(\begin{bmatrix}l & m & 0 & 0\\0 & 0 & l & m \end{bmatrix}\)