The karyotype in klinefelter's syndrome is:

The correct answer is Option (3) → 44 + XXY

Option (3) 44 + XXY — Correct. In Klinefelter’s syndrome the person has one extra X chromosome, so the sex chromosomes are XXY in place of XY. With the 44 autosomes this gives 44 + XXY, which NCERT writes as 47, XXY (47 chromosomes in all). Such a person develops as a male, but some female features also appear, such as development of the breasts (gynaecomastia), and the person is sterile.

NCERT Extract:
Chromosomal Disorders – “… Klinefelter’s Syndrome : This genetic disorder is also caused due to the presence of an additional copy of X-chromosome resulting into a karyotype of 47, XXY. Such an individual has overall masculine development, however, the feminine development (development of breast, i.e., Gynaecomastia) is also expressed (Figure 4.17 a).”

Figure 4.17 Diagrammatic representation of genetic disorders due to sex chromosome composition in humans : (a) Klinefelter Syndrome; (b) Turner’s Syndrome