The contraceptive method which is least reliable is
withdrawal method
The correct option is A.
The explanation for correct option:
Withdrawal method:
The explanation for incorrect options:
Option B:
The diaphragm or cervical cap acts as a mechanical barrier and prevents the entry of sperm into the cervix. This method can also rely on a greater extent.
Option C:
IUD’s
Option D:
A condom is a thin rubber covering which is used by a man to prevent the passage of sperm into the female genital tract. It is still one of the popular and effective methods
Hence, the withdrawal method is the least reliable method.