The correct option is A Detecting genetic abnormality
Amniocentesis is a medical procedure in which amniotic fluid (the protective fluid seen around the foetus) is used to detect the genetic abnormality of the foetus.
This procedure can also be used to detect the sex of the unborn foetus, but, this is unethical and is not allowed to do. Therefore, the permissible use of the technique "amniocentesis" is detecting genetic abnormality.