`(--CH_(2)-overset(CH_(3))overset("| ")underset(CH_(3))underset("| ")"C "-CH_(2)-overset(CH_(3))overset("| ")underset(CH_(3))underset("| ")"C "--)_(n)` is a polymer having monomer units ____________.

Options

A.
B.
C.
D.

Explanation

To identify the monomer unit of the given polymer, we will break down the structure step by step.

### Step-by-Step Solution:

1. **Identify the Structure of the Polymer**:
The polymer is represented as:
\[ (CH_2 - C(CH_3) - C(CH_3) - CH_2 - C(CH_3) - C(CH_3))_n \]
This indicates that the polymer consists of repeating units.

2. **Analyze the Repeating Unit**:
From the structure, we can see that each repeating unit has:
- A carbon atom (C) connected to two methyl groups (CH₃) and a CH₂ group.
- The structure can be simplified to focus on the repeating unit.

3. **Write the Monomer Unit**:
The repeating unit can be identified as:
\[ H_2C = C(CH_3)(CH_3) \]
This indicates that the monomer unit consists of:
- One carbon atom (C) with a double bond to another carbon atom (C).
- Two methyl groups (CH₃) attached to the second carbon.

4. **Final Monomer Unit Representation**:
Thus, the monomer unit can be represented as:
\[ CH_2 = C(CH_3)_2 \]
This indicates that the polymer is made from the monomer unit containing a double bond and two methyl groups.

5. **Conclusion**:
The monomer unit of the given polymer is:
\[ CH_2 = C(CH_3)(CH_3) \]

### Answer:
The monomer units of the polymer are \( CH_2 = C(CH_3)(CH_3) \).