In which of the following techniques is the ovum of a donor is transferred into the fallopian tube of a surrogate mother?

Gamete Intrafallopian Transfer is a procedure for females who are unable to produce an ovum, but can provide a suitable environment for the embryo to develop. In such cases, the ovum from the donor female is implanted into the female's fallopian tubes. 

IVF stands for in-vitro fertilisation. This procedure extracts sperm from the male (or donor) and ovum from the female (or donor). The ovum is subsequently fertilised on a petri dish in the laboratory. 

Embryo transfer, or ET, is the process that follows IVF. The embryo, up to the 8-blastomeres stage, is transferred into the fallopian tube. 

Intra Uterine Transfer is a procedure in which an embryo with at least eight blastomeres is transplanted to the uterine wall for nutrition and to complete its further development.

ZIFT stands for zygote intrafallopian transfer, a method used to treat infertility. An egg fertilised in-vitro (outside the body) is implanted into the fallopian tube of a woman.