Grand old man of intestine is

Options

A. Trypanosoma
B. Entamoeba
C. Giardia
D. E. coli

Answer

To solve the question "Grand old man of intestine is," we need to identify which organism is commonly referred to by this title among the given options.

### Step-by-Step Solution:

1. **Understand the Options**: We have four options to consider:
- A) Trypanosoma
- B) Entamoeba
- C) Giardia
- D) E. coli

2. **Identify the Organisms**:
- **Trypanosoma**: This is a genus of protozoa known to cause diseases like sleeping sickness. It is not typically associated with the intestine.
- **Entamoeba**: This is another genus of protozoa, with Entamoeba histolytica being known for causing amoebic dysentery. While it is related to intestinal infections, it is not referred to as the "grand old man."
- **Giardia**: This is a protozoan parasite that causes giardiasis, an intestinal infection. It is often referred to as the "grand old man of the intestine" due to its historical significance and prevalence in gastrointestinal infections.
- **E. coli**: This is a type of bacteria commonly found in the intestines of humans and animals. While it plays a role in gut health, it is not referred to as the "grand old man."

3. **Determine the Correct Answer**: Based on the above analysis, the organism that is referred to as the "grand old man of the intestine" is **Giardia**.

### Final Answer:
The grand old man of the intestine is **Giardia**.

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