All the following are uses of amniocentesis,but one is a misuse. Which one is a misuse?

• A
  The centres for genetic counselling offer amniocentesis on request to women for chromosome analysis.
• B
  This technique has been developed for detecting foetal abnormalities by analysing chromosomal defects.
• C
  It is used to study metabolic defects of the foetus like $PKU$ (phenylketonuria).
• D
  It is done to examine the sex of the foetus leading to increasing female foeticide.