Choice A rationale:

Almond-shaped eyes are a common physical characteristic associated with Down syndrome.

These distinctive eye features are often seen in individuals with the condition.

Choice B rationale:

Low muscle tone is another common physical characteristic of Down syndrome.

This condition, also known as hypotonia, results in reduced muscle strength and can impact motor skills and coordination in individuals with Down syndrome.

Choice C rationale:

While an extra copy of chromosome 21 is the underlying genetic cause of Down syndrome, this is not a physical characteristic that can be observed directly.

It is a genetic abnormality that leads to the physical features associated with Down syndrome.

Choice D rationale:

A prominent nasal bridge is not a common physical characteristic of Down syndrome.

Individuals with Down syndrome may have flatter nasal bridges, which is one of the facial features associated with the condition.

Choice E rationale:

High muscle tone is not a common characteristic of Down syndrome.

In fact, low muscle tone (hypotonia) is more typical in individuals with Down syndrome and can affect their motor development and physical abilities.