Preparation of organosilicones from `SiCl_(4)` involves substituion in first step:
`SiCl_(4)+xRMgCl to (R)_(x) SiCl_(4-x)+xMgCl_(2)`
Values of 'x' to obtain chain terminating & chain multiplication parts of chain silicone produced are respectively:

Options

A. 1&2
B. 2&1
C. 2&3
D. 3&2

Explanation

To solve the question regarding the preparation of organosilicones from SiCl₄, we need to analyze the reaction and determine the values of 'x' for chain terminating and chain multiplication parts of the silicone produced.

### Step-by-Step Solution:

1. **Understand the Reaction**:
The reaction given is:
\[ \text{SiCl}_4 + x \text{RMgCl} \rightarrow (R)_x \text{SiCl}_{4-x} + x \text{MgCl}_2 \]
Here, SiCl₄ (silicon tetrachloride) reacts with x moles of RMgCl (an organomagnesium compound).

2. **Identify the Products**:
The products of this reaction are:
- \( (R)_x \text{SiCl}_{4-x} \): This represents an organosilicone compound where 'R' groups are attached to silicon.
- \( x \text{MgCl}_2 \): This is magnesium dichloride.

3. **Determine Chain Termination and Chain Multiplication**:
- **Chain Terminating Part**: This part of the silicone structure will have 3 R groups attached to silicon and one chlorine atom remaining. This means that for the chain terminating part, we have:
\[ \text{Si} \text{(R)}_3 \text{Cl} \]
Here, the value of x for the chain terminating part is 3 (since there are 3 R groups).

- **Chain Multiplication Part**: This part will have 2 R groups attached to silicon and 2 chlorine atoms remaining. This means that for the chain multiplication part, we have:
\[ \text{Si} \text{(R)}_2 \text{Cl}_2 \]
Here, the value of x for the chain multiplication part is 2 (since there are 2 R groups).

4. **Final Values**:
Therefore, the values of 'x' for the chain terminating and chain multiplication parts of the silicone produced are:
- Chain Terminating: x = 3
- Chain Multiplication: x = 2

### Conclusion:
The final answer is:
- For chain terminating part: **3**
- For chain multiplication part: **2**