In which of the following techniques, the embryos are transferred to assist those females who cannot conceive?

ZYGOTE INTRA-FALLOPIAN TRANSFER (ZIFT): It is also one of the assisted methods of conception. The procedure for ZIFT is similar to IVF-ET. In this method, after In-vitro fertilization, the zygote is transferred into the fallopian tube. After the transfer of the zygote early stages of development, implantation, and maintenance of pregnancy take place in the normal method. 

INTRAUTERINE TRANSFER (IUT): In this technique, after in-vitro fertilization, the zygote is allowed to develop into an embryo (more than eight blastomeres). The embryo is transformed directly into the uterus for implantation and further development. Embryos formed by In-vivo fertilization could be used for such transfer to assist those females who fail to conceive.