## Core Concept
Androgen insensitivity syndrome (AIS) is a condition that results from mutations in the androgen receptor gene, leading to an inability of cells to respond to androgens. This condition affects sexual development in individuals with a 46,XY karyotype, causing them to develop female external genitalia despite the presence of testes.

## Why the Correct Answer is Right
Individuals with AIS have a 46,XY karyotype and testes that produce androgens, but due to the androgen receptor defect, their bodies are unable to respond to these hormones. As a result, they develop female external genitalia and typically present with primary amenorrhea and infertility. The condition is characterized by a female phenotype with a lack of pubic and axillary hair.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is not provided, so it cannot be evaluated.
- **Option B:** This option is not provided, so it cannot be evaluated.
- **Option C:** This option is not provided, so it cannot be evaluated.
- **Option D:** This option is not provided, so it cannot be evaluated.

## Clinical Pearl / High-Yield Fact
A key clinical pearl regarding AIS is that affected individuals often have a short blind-ending vagina and may lack a uterus and fallopian tubes due to the presence of Müllerian inhibiting substance (MIS) produced by the testes during fetal development. This condition is a classic cause of primary amenorrhea and should be considered in the differential diagnosis of individuals with female external genitalia and a 46,XY karyotype.

## Correct Answer: B.