`C_8H_8Cl_2(A)overset("Aq. NaoH")rarr(B)overset("Mild reduction")rarr(C)overset(l_2//NaOH)rarr"iodoform + acid salt" (D)`

Options

A. `PhCOCH_3`
B. `PhCH(OH)CH_3`
C. PhCOONa
D. `PhC(Cl)_2CH_3`

Explanation

To solve the problem step by step, we will analyze the reactions involved in transforming compound A (C8H8Cl2) into compound D (iodoform + acid salt).

### Step 1: Identify Compound A
Compound A is given as C8H8Cl2. This can be represented as a structure that includes a phenyl group (C6H5) and two chlorine atoms attached to it, along with a methyl group (CH3). The structure can be drawn as follows:

\[ \text{C}_6\text{H}_5\text{CCl}_2\text{CH}_3 \]

### Step 2: Reaction with Aqueous NaOH
When compound A is treated with aqueous NaOH, a nucleophilic substitution reaction occurs. The hydroxide ions (OH-) from NaOH will replace the chlorine atoms (Cl) in the compound.

The reaction can be represented as:
\[ \text{C}_6\text{H}_5\text{CCl}_2\text{CH}_3 + 2 \text{NaOH} \rightarrow \text{C}_6\text{H}_5\text{C(OH)}_2\text{CH}_3 + 2 \text{NaCl} + \text{HCl} \]

However, since two OH groups cannot remain in the same position, one water molecule is eliminated, leading to the formation of a carbonyl compound (ketone).

The resulting compound B is:
\[ \text{C}_6\text{H}_5\text{C(=O)CH}_3 \]

### Step 3: Mild Reduction of Compound B
Next, compound B undergoes mild reduction. In this step, the carbonyl group (C=O) is reduced to a hydroxyl group (C-OH).

The reaction can be represented as:
\[ \text{C}_6\text{H}_5\text{C(=O)CH}_3 + \text{H}_2 \rightarrow \text{C}_6\text{H}_5\text{C(OH)CH}_3 \]

The resulting compound C is:
\[ \text{C}_6\text{H}_5\text{C(OH)CH}_3 \]

### Step 4: Reaction of Compound C with I2 and NaOH
Finally, compound C is treated with iodine (I2) and sodium hydroxide (NaOH). This reaction leads to the formation of iodoform (CHI3) and an acid salt.

The reaction can be represented as:
\[ \text{C}_6\text{H}_5\text{C(OH)CH}_3 + \text{I}_2 + \text{NaOH} \rightarrow \text{iodoform} + \text{acid salt} \]

### Conclusion
Now we can summarize the compounds:
- A: C8H8Cl2 = C6H5CCl2CH3
- B: C6H5C(=O)CH3
- C: C6H5C(OH)CH3
- D: Iodoform + Acid Salt

### Final Answer
The compound B is:
\[ \text{B} = \text{C}_6\text{H}_5\text{C(=O)CH}_3 \]