Option 1: Down`s syndrome is a genetic disorder that is caused by the presence of an extra copy of chromosome 21. It is characterized by several physical characteristics such as low muscle tone, upward slanting eyes, and a flat facial profile, but not webbed neck.

Option 2: Turner`s syndrome is a genetic disorder that affects females. It is caused by the absence or partial absence of one of the X chromosomes. One of the characteristic features of Turner`s syndrome is a webbed neck. This refers to extra folds of skin on the back of the neck that give the appearance of a web-like structure.

Option 3: Klinefelter`s syndrome is a genetic disorder that affects males. It is caused by the presence of an extra X chromosome. Some physical features associated with Klinefelter`s syndrome include tall stature and small testicles, but not webbed neck.

Option 4: Cri-du-chat syndrome is a rare genetic disorder caused by a deletion on the short arm of chromosome 5. It is characterized by a high-pitched cry that sounds like a cat, intellectual disability, and distinctive facial features. Webbed neck is not a characteristic of this syndrome.

The correct answer is option 2, Turner`s syndrome.