The karyotype of a person with Turner's syndrome is:

The correct answer is Option (2) → 44 + XO

Option (2) 44 + XO — Correct. Turner’s syndrome is caused by the absence of one X chromosome, so the karyotype is 44 + XO, 45 chromosomes in all. Such females are sterile, as the ovaries are rudimentary.

NCERT Extract:
Chromosomal Disorders – “… Turner’s Syndrome : Such a disorder is caused due to the absence of one of the X chromosomes, i.e., 45 with X0, Such females are sterile as ovaries are rudimentary besides other features including lack of other secondary sexual characters (Figure 4.17 b).”