## Core Concept
Lymphomas are a type of cancer that originates from lymphocytes, which are a subset of white blood cells. In children, lymphomas are one of the most common types of cancer. The age distribution of lymphomas in children is an important aspect of pediatric oncology.

## Why the Correct Answer is Right
The correct answer, **B. 5-10 years**, reflects the peak age range for the incidence of lymphoma in children. Lymphomas can occur at any age, but in children, they predominantly occur in the 5-10 years age group. This age distribution is relevant for both Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL), which are the two main types of lymphomas. **Hodgkin lymphoma** tends to peak in late adolescence and young adulthood, but within the pediatric population, it also significantly occurs in children aged 5-10. **Non-Hodgkin lymphoma** has a different age distribution but also peaks within this range.

## Why Each Wrong Option is Incorrect
* **Option A: 15 years** - This option refers to an age group that is generally considered adolescent and young adult, rather than pediatric. While lymphomas do occur in this age group, the question specifically asks about children.

## Clinical Pearl / High-Yield Fact
A key point to remember is that lymphomas are highly treatable and often curable, especially when detected early. The two main types, **Hodgkin lymphoma** and **non-Hodgkin lymphoma**, have different prognoses and treatments, making accurate diagnosis and staging critical.

## Correct Answer: B. 5-10 years.