An organic compound A has the molecular formula of `C_7H_6O`. When A is treated with NaOH followed by acid hydrolysis, it gives two products, B and C. When B is oxidised, it gives A. When A and C are each treated separately with `PCl_5`, they give two different organic products D and E.
Give the chemical reaction when A is treated with NaOH and name the reaction.

Explanation

To solve the problem step by step, we will analyze the organic compound A with the molecular formula C7H6O, identify its structure, and describe the reactions involved.

### Step 1: Identify the compound A
The molecular formula C7H6O suggests that compound A is likely benzaldehyde (C6H5CHO), which is a common organic compound with this formula.

### Step 2: Reaction of A with NaOH
When benzaldehyde (A) is treated with sodium hydroxide (NaOH), it undergoes a reaction known as the **Cannizzaro reaction**. In this reaction, benzaldehyde does not have an alpha-hydrogen, so it cannot undergo aldol condensation. Instead, it disproportionates in the presence of a strong base.

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