Bacillus thuringiensis is widely used as :

Options

A. Insecticide
B. Weedicides
C. Rodenticide
D. None of the above

Answer

**Step-by-Step Solution:**

1. **Identify Bacillus thuringiensis (Bt):**
- Bacillus thuringiensis is a bacterium that produces a toxin harmful to certain insects. It is often abbreviated as Bt.

2. **Understand its Function:**
- The toxin produced by Bacillus thuringiensis is specifically designed to target the gut of certain insects. When these insects ingest the toxin, it becomes activated in their digestive system, leading to the breakdown of their gut cells and ultimately causing their death.

3. **Applications in Agriculture:**
- Due to its insecticidal properties, Bacillus thuringiensis is widely used in agriculture. It is often genetically engineered into crops (like Bt cotton) to provide them with resistance against pest attacks.

4. **Evaluate the Options:**
- A. Insecticide: This is correct, as Bt is used to kill insects.
- B. Budicides: This option is not relevant to Bacillus thuringiensis.
- C. Rodenticide: This is incorrect, as Bt does not target rodents.
- D. None of the above: This is also incorrect since option A is valid.

5. **Conclusion:**
- The correct answer to the question is **A. Insecticide**.