Tissue Containing Totipotent Embryonic Stem Cells Is Difficult to Obtain;

Multiple Choice

Tissue containing totipotent embryonic stem cells is difficult to obtain; what is the usual source?

A) donated blastocysts produced by in vitro fertilization for women seeking fertility treatment
B) tissues from spontaneous miscarriage during the first trimester of pregnancy
C) blood and tissues extracted from the placenta after the birth of the fetus
D) cloned embryos produced by fusing a somatic cell with an enucleated egg cell