The correct option is D A combination of superovulation, artificial insemination and embryo transplantation into a carrier cow (surrogate mother)
Superovulation, also known as controlled ovarian hyper stimulation, is the process of inducing a female to release more than one egg in a month by injecting hormone.
Artificial insemination is the technique in which semen with living sperms is collected from the male and introduced into female reproductive tract at the proper time with the help of instruments.
After artificial insemination 4 to 10 embryos are collected at a time. Then each embryo is transplanted into a surrogate mother “carrier cow”. As all the methods have been used for increasing the productivity of super milch cow.
So the correct answer is "option D".