The correct option is B Sex ratio
Amniocentesis (also referred to as amniotic fluid test or AFT) is a medical procedure used in prenatal diagnosis of chromosomal abnormalities and foetal infections, and also used for sex determination in which a small amount of amniotic fluid, which contains foetal tissues, is sampled from the amniotic sac surrounding a developing foetus, and the foetal DNA is examined for genetic abnormalities. This technique is affecting the sex ratio as, some people in desire of baby boy prefer the abortion of the girl child after knowing the sex. So, the correct option is B.