Step 1: Understanding the Concept
MOET stands for multiple ovulation embryo transfer. It is used to increase herd size quickly.
Step 2: The procedure
A high-yielding cow is given FSH-like hormones so that it releases 6-8 eggs in one cycle. It is then mated with an elite bull or artificially inseminated.
Step 3: Stage of transfer
The embryos are flushed out non-surgically when they reach the 8-32 celled stage and are placed in surrogate mothers.
Step 4: Conclusion
Embryos are implanted at the 8 to 32 celled stage.
Final Answer:
Embryos are implanted at the 8 to 32 celled stage.
\[ \boxed{\text{(C) }\text{8 to 32 celled embryos}} \]