**Core Concept**
Turner syndrome is a genetic disorder that affects females, characterized by the partial or complete absence of one X chromosome. This results in a 45,X karyotype, leading to various physical and developmental abnormalities.

**Why the Correct Answer is Right**
Turner syndrome is associated with short stature, ovarian dysgenesis, and heart defects. The lack of a second X chromosome leads to the inactivation of the single X chromosome, resulting in the silencing of genes that are essential for normal female development. The short stature is due to the growth hormone deficiency and the ovarian dysgenesis is due to the absence of estrogen production.

**Why Each Wrong Option is Incorrect**
**Option A:** While Turner syndrome is associated with heart defects, it is not the most common cardiovascular anomaly. The most common heart defect in Turner syndrome is bicuspid aortic valve, but this is not the hallmark feature of the condition.

**Option B:** Infertility is a common feature of Turner syndrome due to ovarian dysgenesis, but it is not the primary characteristic that defines the condition.

**Option C:** While Turner syndrome is associated with developmental delays, it is not the most distinctive feature of the condition. Individuals with Turner syndrome may have normal intelligence, but they may have difficulties with social and emotional development.

**Clinical Pearl / High-Yield Fact**
Turner syndrome is often associated with a cubitus valgus deformity (carpals and tarsals are also affected) and a low posterior hairline, which are key physical examination findings.

**Correct Answer: B. Infertility is a common feature of Turner syndrome due to ovarian dysgenesis.**