which of the following is a casual organism of leaf spot of rice that caused Bengal famine in 1942- 43?

Options

A. Fusarium oxysporum
B. Trichophyton interdigitate
C. Alternaria solani
D. Helminthosporium oryzae

Answer

To solve the question regarding the causal organism of leaf spot of rice that caused the Bengal famine in 1942-43, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for the causal organism of the leaf spot disease of rice that led to the Bengal famine in 1942-43.

2. **Identify the Context**: The Bengal famine of 1942-43 was a significant historical event where millions of people died due to starvation, largely attributed to crop failures, particularly rice.

3. **Recall Relevant Information**:
- The disease affecting rice that led to this famine is known as a leaf spot disease.
- We need to identify which of the given options is a fungal organism responsible for this disease.

4. **Evaluate the Options**:
- **Fusarium**: Generally associated with various plant diseases but not specifically known for rice leaf spot.
- **Oxysporum**: This is a genus of fungi but not the one responsible for the leaf spot of rice.
- **Trichophyton**: This is a genus of fungi that primarily affects humans and animals, not plants.
- **Alternaria solani**: This fungus is known for affecting solanaceous plants, not rice.
- **Helminthosporium oryzae**: This is a well-known fungal pathogen that causes leaf spot disease in rice and is historically linked to the Bengal famine.

5. **Select the Correct Answer**: Based on the evaluation, the correct answer is **Helminthosporium oryzae**.

### Final Answer:
The causal organism of leaf spot of rice that caused the Bengal famine in 1942-43 is **Helminthosporium oryzae**.