Only embryo up to 8 blastomeres if zygote is not transplanted.
Only zygote is transplanted not embryo.
Either zygote or embryo with 8 blastomere phase transplanted.
Morula with 8-24 celled stage is transplanted in fallopian tube.
After the fusion of male and female gametes in the lab, the zygote is transferred to the fallopian tube only after it reaches the 8 blastomere phase. This is done so as to ensure the chances of successful implantation. So the correct answer is 'Either zygote or embryo with 8 blastomere phase transplanted'.