The correct option is C Ultrasound
Amniocentesis is a medical procedure used in prenatal diagnosis of chromosomal abnormalities and fetal infections, and also for sex determination. Similarly and USG or ultrasound scan which can be used to visualize live images of the developing fetus can also be used in sex determination. And in India this information is misused to determine whether the fetus is a female and can lead to female foeticide.