Match the following list of bacteria and their commercially important products.
`{:("Bacterium","Product"),((i)"Aspergillus niger",(A)"Lactic acid"),((ii)"Acetobacter aceti",(B)"Butyric acid"),((iii)"Clostridium butylicum",(C)"Acetic acid"),((iv)"Lactobacillus",(D)"Citric acid"):}`
Choose the correct match.

Options

A. `i-(B),ii-(C),iii-(D),iv-(A)`
B. `i-(B),ii-(D),iii-(C),iv-(A)`
C. `i-(D),ii-(C),iii-(B),iv-(A)`
D. `i-(D),ii-(A),iii-(C),-iv-(B)`

Answer

To solve the problem of matching the bacteria with their commercially important products, we will analyze each bacterium and its corresponding product step by step.

### Step-by-Step Solution:

1. **Identify Aspergillus niger**:
- Aspergillus niger is a fungus, not a bacterium. It is primarily known for its role in the production of citric acid.
- **Match**: Aspergillus niger → (D) Citric acid.

2. **Identify Acetobacter aceti**:
- Acetobacter aceti is a bacterium that is known for converting ethanol into acetic acid through the process of oxidation.
- **Match**: Acetobacter aceti → (C) Acetic acid.

3. **Identify Clostridium butylicum**:
- Clostridium butylicum is a bacterium that is involved in the production of butyric acid through fermentation processes.
- **Match**: Clostridium butylicum → (B) Butyric acid.

4. **Identify Lactobacillus**:
- Lactobacillus is a group of bacteria that are known for their role in the production of lactic acid, especially in the fermentation of dairy products.
- **Match**: Lactobacillus → (A) Lactic acid.

### Final Matching:
- (i) Aspergillus niger → (D) Citric acid
- (ii) Acetobacter aceti → (C) Acetic acid
- (iii) Clostridium butylicum → (B) Butyric acid
- (iv) Lactobacillus → (A) Lactic acid

### Summary of Matches:
- (i) Aspergillus niger - (D) Citric acid
- (ii) Acetobacter aceti - (C) Acetic acid
- (iii) Clostridium butylicum - (B) Butyric acid
- (iv) Lactobacillus - (A) Lactic acid