The total number of compounds from below when treated with hot KMnO4 giving benzoic acid is:
Identify product [A], [B], and [C] in the following reaction sequence.
If the value of \( \cos \alpha \) is \( \frac{\sqrt{3}}{2} \), then \( A + A = I \), where \[ A = \begin{bmatrix} \sin\alpha & -\cos\alpha \\ \cos\alpha & \sin\alpha \end{bmatrix}. \]