While teaching anticipatory guidance to a young couple with a child with Down syndrome, the nurse explains that one major physical characteristic of the child with Down syndrome is:

A. Children with Down syndrome typically exhibit short stature, not excessive height. B. While children with Down syndrome may have a single transverse palmar crease, not "spots on the palms," this is not the most defining physical feature. C. One of the hallmark physical characteristics of Down syndrome is hypotonia (low muscle tone). It often leads to delayed motor development, poor head control, and floppy posture in infancy. D. Children with Down syndrome are more likely to have hyperflexible joints due to ligamentous laxity, not inflexibility.