Double helix model of DNA which was proposed by watson and crick was of-

Options

A. `C-DNA`
B. `B-DNA`
C. `D-DNA`
D. `Z-DNA`

Answer

To answer the question regarding the double helix model of DNA proposed by Watson and Crick, we can follow these steps:

### Step 1: Identify the model proposed by Watson and Crick
Watson and Crick proposed the double helix model of DNA, which describes the structure of DNA as two strands that coil around each other.

### Step 2: Understand the types of DNA
There are several forms of DNA, primarily classified as A-DNA, B-DNA, and Z-DNA. Each form has distinct structural characteristics:
- **A-DNA**: Right-handed helix, more compact than B-DNA.
- **B-DNA**: Right-handed helix, the most common and physiologically relevant form of DNA.
- **Z-DNA**: Left-handed helix, which is less common and has a zigzag shape.

### Step 3: Determine the correct answer
The question specifically asks about the model proposed by Watson and Crick. The double helix model they described corresponds to **B-DNA**.

### Conclusion
Thus, the correct answer to the question is **B-DNA**.

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