Out of the following, the alkene that exhibits optical isomerism is
3-methyl-2-pentene
4-methyl-1-pentene
3-methyl-1-pentene
2-methyl-2-pentene

Options

A. 3-methyl-2-pentene
B. 4-methyl-1-pentene
C. 3-methyl-1-pentene
D. 2-methyl-2-pentene

Explanation

To determine which alkene exhibits optical isomerism, we will analyze each of the given compounds for the presence of chiral centers. A chiral center is typically a carbon atom that is bonded to four different groups.

### Step-by-step Solution:

1. **Identify the Structures of Each Alkene:**
- **3-methyl-2-pentene:**
- Structure: CH3-CH(CH3)-CH=CH-CH3
- The double bond is between the second and third carbon atoms.
- **4-methyl-1-pentene:**
- Structure: CH2=CH-CH2-CH(CH3)-CH3
- The double bond is between the first and second carbon atoms.
- **3-methyl-1-pentene:**
- Structure: CH2=CH-CH(CH3)-CH2-CH3
- The double bond is between the first and second carbon atoms.
- **2-methyl-2-pentene:**
- Structure: CH3-C(CH3)=CH-CH3
- The double bond is between the second and third carbon atoms.

2. **Check for Chiral Centers:**
- **3-methyl-2-pentene:**
- No carbon has four different substituents. Thus, it has no chiral centers.
- **4-methyl-1-pentene:**
- No carbon has four different substituents. Thus, it has no chiral centers.
- **3-methyl-1-pentene:**
- The third carbon (C3) has four different groups: CH3, H, CH2, and CH=CH2. Thus, it has one chiral center.
- **2-methyl-2-pentene:**
- The second carbon (C2) has two identical methyl groups (CH3) attached. Thus, it has no chiral centers.

3. **Conclusion:**
- The only alkene that exhibits optical isomerism due to the presence of a chiral center is **3-methyl-1-pentene**.

### Final Answer:
The alkene that exhibits optical isomerism is **3-methyl-1-pentene**.