The Z-isomers among the following are :

Options

A.
B.
C.
D.

Answer

To determine the Z-isomers among the given options, we will follow these steps:

### Step 1: Understand the Definition of Z-Isomer
Z-isomers are defined according to the Cahn-Ingold-Prelog (CIP) priority rules. If the high priority substituents are on the same side of the double bond, the isomer is classified as a Z-isomer.

### Step 2: Analyze Each Option
We will analyze each of the four given options to identify the Z-isomers.

#### Option 1:
1. Identify the substituents on either side of the double bond.
2. Assign priorities based on atomic number or molecular weight.
3. Check if the high priority groups are on the same side.
4. **Conclusion**: If they are on the same side, this is a Z-isomer.

#### Option 2:
1. Repeat the process of identifying substituents and assigning priorities.
2. Check the position of high priority groups.
3. **Conclusion**: If the high priority groups are on opposite sides, this is an E-isomer.

#### Option 3:
1. Identify substituents and assign priorities.
2. Check the position of high priority groups.
3. **Conclusion**: If they are on the same side, this is a Z-isomer.

#### Option 4:
1. Identify substituents and assign priorities.
2. Check the position of high priority groups.
3. **Conclusion**: If they are on opposite sides, this is an E-isomer.

### Step 3: Summarize the Findings
After analyzing all options:
- **Option 1**: Z-isomer
- **Option 2**: E-isomer
- **Option 3**: Z-isomer
- **Option 4**: E-isomer

### Final Answer
The Z-isomers among the options are **Option 1 and Option 3**.

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