The correct answer is option 1: 44A+XO.

Turner syndrome is a genetic disorder that only affects females. It is caused by the complete or partial absence of one of the X chromosomes. In Turner syndrome, one of the X chromosomes is missing or abnormal, resulting in a total of 45 chromosomes instead of the usual 46. The "44A" designation refers to the normal autosomes, while "XO" indicates the absence of one X chromosome.

Option 2, 44A+XXX, is not correct as it represents triple X syndrome, a different genetic condition where females have three X chromosomes instead of the usual two.

Option 3, 44A+XXY, represents Klinefelter syndrome, a condition where males have an additional X chromosome.

Option 4, 44A+XYY, represents Jacobs syndrome, where males have an additional Y chromosome.

Therefore, the correct designation for Turner syndrome is 44A+XO.