The presence of additional copy of X chromosome in humans lead to

The correct answer is Option (2) → Klinefelter's Syndrome

Option (2) Klinefelter's Syndrome — Correct. Of the options, only Klinefelter’s syndrome comes from an extra X chromosome (47, XXY). Down’s syndrome is trisomy of 21, and Turner’s syndrome lacks one X chromosome (45 with X0).

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