The symptoms described in the question are characteristic of Down syndrome, a genetic disorder caused by the presence of an extra copy of chromosome 21. This results in a trisomy of chromosome 21.

Option A : Trisomy of chromosome 21 - Individuals with Down syndrome typically exhibit a range of physical and developmental features, such as a small round head, furrowed tongue, partially open mouth, and a broad palm with a characteristic single palmar crease. They also tend to have delayed physical, psychomotor, and mental development. Karyotype analysis of an individual with Down syndrome will show three copies of chromosome 21 instead of the normal two copies.

The other options describe different chromosomal abnormalities:

Option B : 47 chromosomes with XXY sex chromosomes - This karyotype is characteristic of Klinefelter syndrome, a condition in which males have an extra X chromosome. Affected individuals have 47 chromosomes, and their symptoms are different from those described in the question.

Option C : 45 chromosomes with XO sex chromosomes - This karyotype is characteristic of Turner syndrome, a condition in which females have only one X chromosome. Affected individuals have 45 chromosomes, and their symptoms are different from those described in the question.

Option D : 47 chromosomes with XYY sex chromosomes - This karyotype is characteristic of XYY syndrome, a condition in which males have an extra Y chromosome. Affected individuals have 47 chromosomes, and their symptoms are different from those described in the question.