## Core Concept
Down's syndrome, also known as Trisomy 21, is a genetic disorder caused by the presence of an extra copy of chromosome 21. This condition leads to various physical and developmental delays. The core concept here revolves around understanding the characteristics and genetic basis of Down's syndrome.

## Why the Correct Answer is Right
The correct answer option is not directly provided, but we can infer that the question seeks an incorrect statement regarding Down's syndrome. Typically, characteristics of Down's syndrome include intellectual disability, delayed speech, distinct facial features, and an increased risk of certain medical conditions. Any statement contradicting these established facts or misrepresenting the genetic or clinical aspects of Down's syndrome would be considered not true.

## Why Each Wrong Option is Incorrect
Without specific details on options A, B, C, and D, we can still provide a general approach to evaluating incorrect statements about Down's syndrome:
- **Option A:** If a statement claims that Down's syndrome is caused by a single gene mutation, it would be incorrect because Down's syndrome is primarily caused by trisomy of chromosome 21, not a single gene mutation.
- **Option B:** If a statement suggests that Down's syndrome is exclusively inherited from parents, it would be misleading because while there is a parental age-related risk, the condition often occurs sporadically.
- **Option C:** If a statement proposes that individuals with Down's syndrome have a normal life expectancy, it would be incorrect as, although life expectancy has increased, it is generally shorter than that of the general population.
- **Option D:** If a statement indicates that Down's syndrome can be cured by a specific medication or intervention, it would be incorrect because, currently, there is no cure, only management of symptoms and associated conditions.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the risk of having a child with Down's syndrome increases with advanced maternal age. Additionally, screening tests during pregnancy, such as the non-invasive prenatal test (NIPT) and invasive diagnostic tests like amniocentesis, can detect Down's syndrome. Early intervention and supportive care can significantly improve the quality of life for individuals with Down's syndrome.

## Correct Answer: D.