For purpose of curdling, an inoculum is added to the milk. This inoculum contains:

Options

A. Bacteria
B. Lactic acid
C. Flavouring agent
D. Vitamin `B_(12)`

Answer

**Step-by-Step Solution:**

1. **Understanding the Process of Curdling:**
- Curdling is a process where milk is transformed into curd. This is typically done by adding an inoculum to the milk.

2. **Identifying the Inoculum:**
- The inoculum used for curdling milk primarily consists of specific bacteria that facilitate this transformation.

3. **Recognizing the Key Bacteria:**
- The main bacteria involved in the curdling process is *Lactobacillus*. This bacterium plays a crucial role in converting lactose (the sugar present in milk) into lactic acid.

4. **Role of Lactic Acid:**
- The production of lactic acid from lactose leads to the coagulation of milk proteins, resulting in the formation of curd.

5. **Evaluating the Options:**
- Given the options:
- a) Bacteria
- b) Lactic acid
- c) Flavoring agent
- d) Vitamin B12
- The correct answer is option (a) Bacteria, specifically *Lactobacillus*.

6. **Conclusion:**
- Therefore, the inoculum added to milk for curdling primarily contains bacteria, particularly *Lactobacillus*.

**Final Answer:**
The inoculum added to the milk for curdling contains bacteria (specifically *Lactobacillus*).

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