In 1997, Dolly the Sheep Was Cloned

Multiple Choice

In 1997, Dolly the sheep was cloned. Which of the following processes was used?

A) replication and dedifferentiation of adult stem cells from sheep bone marrow
B) separation of an early stage sheep blastula into separate cells, one of which was incubated in a surrogate ewe
C) transfer of an adult cell's nucleus into an enucleated sheep egg, followed by incubation in a surrogate
D) isolation of stem cells from a lamb embryo and production of a zygote equivalent