The correct option is D Implantation of embryo at site other than uterus
Ectopic pregnancy also termed extrauterine pregnancy, occurs when a fertilized egg grows and develops at some other place in the female reproductive system other than the uterus. This may lead to life-threatening bleeding and requires medical attention immediately. In the majority of the events, it is in the fallopian tube that the egg implants itself. This is known as tubal pregnancy and happens generally within the first few weeks of gestation.