A. At 8 weeks, the embryo is transitioning into the fetal stage of development and is not viable outside the womb. Organs are still in the early stages of formation. B. While some sources may consider 24 weeks the age of "reasonable viability" with intensive medical support, many medical guidelines recognize viability beginning as early as 20 weeks under optimal conditions. C. The age of 20 weeks is often cited as the lower threshold of fetal viability due to improved neonatal care, although survival rates improve significantly after this point. D. At 14 weeks, the fetus is in the second trimester, but it is far too underdeveloped for survival outside the womb.