The commonest worm in children is

Options

A. Ascaris lumbricoides
B. Enterobios vermicularis
C. Ancylostoma duodenale
D. Trichinella sprialis

Answer

### Step-by-Step Solution:

1. **Identify the Question**: The question asks for the commonest worm found in children.

2. **Understand the Options**: The options provided are likely different types of worms, all belonging to the phylum Aschelminthes (or Nemathelminthes), which are roundworms.

3. **Recognize the Common Worm**: Among the options, the most common worm in children is **Ascaris lumbricoides**. This is known as the giant intestinal roundworm.

4. **Explain the Life Cycle**: Ascaris lumbricoides is an endoparasite that primarily resides in the small intestine. The eggs of this worm can be found in contaminated fruits and vegetables that are not properly washed.

5. **Discuss the Impact on Health**: The presence of Ascaris lumbricoides can lead to a condition known as **Ascariasis**. This can cause various health issues in children, such as abdominal discomfort, constipation, pain, and malnutrition due to the worm feeding on the host's digested food.

6. **Mention Other Worms**: The other options provided (Enterobius vermicularis, Ancylostoma, and Trichinella spiralis) are also types of worms but are not as common in children as Ascaris lumbricoides.

7. **Conclude the Answer**: Therefore, the correct answer to the question is **Ascaris lumbricoides**.

### Final Answer:
The commonest worm in children is **Ascaris lumbricoides**.

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