Match the column-I and column-II
`{:("Column I",,"Column II"),((i)"Viroid",,(a)"Ramachandran"),((ii)"Cell",,(b)"Leewenhoek"),((iii)"Virus",,(c)"T.O.Diener"),((iv)"Triple helical structure of collagen",,(d)"lvanowsky"):}`

Options

A. `i - b , ii - a, iii - c , iv - d`
B. `i - a , ii - b, iii - d , iv - c`
C. `i - c , ii - b, iii - d , iv - a`
D. `i - d, ii - b, iii - c , iv - a`

Answer

To solve the matching question, we need to pair the items from Column I with their corresponding discoveries or contributions in Column II. Let's go through each item step by step:

### Step 1: Match Viroid
- **Viroid**: Viroids are small infectious agents composed of RNA. They were first discovered by **T.O. Diener** in 1971.
- **Match**: (i) Viroid → (c) T.O. Diener

### Step 2: Match Cell
- **Cell**: The concept of the cell was first introduced by **Robert Hooke**, but he observed dead plant cells. The first living cells were observed by **Anton van Leeuwenhoek** in blood and saliva.
- **Match**: (ii) Cell → (b) Leeuwenhoek

### Step 3: Match Virus
- **Virus**: The term "virus" was introduced by **Pasteur** and **Iwanowski** in the context of studying infectious agents. Iwanowski is known for his work on the tobacco mosaic virus.
- **Match**: (iii) Virus → (d) Iwanowski

### Step 4: Match Triple Helical Structure of Collagen
- **Triple Helical Structure of Collagen**: The triple helical structure of collagen was described by **Ramachandran**.
- **Match**: (iv) Triple helical structure of collagen → (a) Ramachandran

### Final Matches:
- (i) Viroid → (c) T.O. Diener
- (ii) Cell → (b) Leeuwenhoek
- (iii) Virus → (d) Iwanowski
- (iv) Triple helical structure of collagen → (a) Ramachandran

### Summary of Matches:
1. Viroid - T.O. Diener
2. Cell - Leeuwenhoek
3. Virus - Iwanowski
4. Triple helical structure of collagen - Ramachandran