## Core Concept
The question tests knowledge of genetic disorders associated with specific chromosomal abnormalities. Chromosome 7 is involved in several genetic disorders, and identifying the correct association requires understanding the clinical and genetic features of these conditions.

## Why the Correct Answer is Right
The correct answer, **Williams Syndrome**, is associated with a deletion on chromosome 7. Williams Syndrome is a genetic disorder characterized by a distinctive "elfin" facial appearance, intellectual disability, and a friendly, outgoing personality. It is caused by a deletion of several genes on chromosome 7, including the gene for elastin, which leads to the characteristic physical and developmental features.

## Why Each Wrong Option is Incorrect
* **Option A:** Cystic Fibrosis is caused by mutations in the CFTR gene located on chromosome 7, but it's more commonly associated with chromosome 7q31. However, the most accurate association for cystic fibrosis is with mutations in the CFTR gene on chromosome 7, but it's actually located on the long arm (7q31.2), yet there's a more specific association for another option.
* **Option B:** This option might relate to other genetic conditions but isn't directly linked to chromosome 7 in a well-known manner like Williams Syndrome.
* **Option D:** This option does not directly relate to a commonly known condition associated with chromosome 7.

## Clinical Pearl / High-Yield Fact
A key clinical pearl is that Williams Syndrome patients often have a unique personality characterized by being overly friendly and social, despite their intellectual disability. This condition is also associated with cardiovascular abnormalities, including supravalvular aortic stenosis.

## Correct Answer: C. Williams Syndrome