The only male is affected in –
**Core Concept**
The question pertains to the field of medical genetics, specifically focusing on **X-linked recessive inheritance**. This pattern of inheritance is characterized by genes located on the X chromosome. **X-linked recessive disorders** typically affect males, as they have only one X chromosome.
**Why the Correct Answer is Right**
Since the correct answer is not explicitly provided, let's discuss the general principle. In **X-linked recessive inheritance**, males are more frequently affected than females because they have only one X chromosome. If that X chromosome carries the mutation for the disorder, they will express the condition since they don't have another X chromosome to compensate.
**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific details of option A, we cannot provide a direct explanation for its incorrectness.
**Option B:** Similarly, without knowing what option B entails, we cannot discuss its inaccuracies.
**Option C:** and **Option D:** also lack specific information to address their incorrectness directly.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that **X-linked recessive disorders** often present with affected males and female carriers who are usually asymptomatic or less severely affected.
**Correct Answer:** D. Haemophilia