Match the column and choose the correct answers:
`{:("Column I","Column II"),(A."Thiobacillus",i." Aerobic Nitrogen-fixation"),(B."Nitrosomonas",ii."Anaerobic Nitrogen Fixation"),(C."Azotobacter",iii."Nitrification"),(D."Clostridium",iv."Denitrificaion"):}`

Options

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

Answer

To solve the matching question, we need to pair the organisms in Column I with the correct nitrogen fixation processes in Column II. Let's break it down step by step.

### Step-by-Step Solution:

1. **Identify the Organisms and Their Functions:**
- **A. Thiobacillus**: This organism is known for its role in denitrification, which is the process of converting nitrates into nitrogen gas.
- **B. Nitrosomonas**: This bacterium is involved in nitrification, specifically converting ammonium ions (NH4+) into nitrite ions (NO2-).
- **C. Azotobacter**: This is a free-living nitrogen-fixing bacterium that performs aerobic nitrogen fixation, meaning it fixes nitrogen in the presence of oxygen.
- **D. Clostridium**: This organism is known for its role in anaerobic nitrogen fixation, which occurs in the absence of oxygen.

2. **Match Each Organism with the Correct Process:**
- **Thiobacillus** (A) → **Denitrification** (iv)
- **Nitrosomonas** (B) → **Nitrification** (iii)
- **Azotobacter** (C) → **Aerobic Nitrogen Fixation** (i)
- **Clostridium** (D) → **Anaerobic Nitrogen Fixation** (ii)

3. **Write Down the Matches:**
- A → iv (Thiobacillus → Denitrification)
- B → iii (Nitrosomonas → Nitrification)
- C → i (Azotobacter → Aerobic Nitrogen Fixation)
- D → ii (Clostridium → Anaerobic Nitrogen Fixation)

4. **Final Matching:**
- The correct pairs are:
- A → iv
- B → iii
- C → i
- D → ii

5. **Select the Correct Option:**
- The correct option that matches all the above pairs is the first option.

### Final Answer:
- The correct matches are:
- A → iv
- B → iii
- C → i
- D → ii