A(n) further develops the organs and systems that existed in rudimentary form in the embryonic stage.

The answer is Fetus.

Explanation:

Human embryonic development refers to the development and formation of the human embryo. A developing human is referred to as Embryo during 3-8 weeks, and Fetus the ninth month of gestation until the birth. At the end of the 8th week after fertilization- embryo is considered a fetus. During this stage, the following are markers during pregnancy:

•    By 12 weeks of pregnancy, The fetus is filled with the entire uterus.

•    By about 14 weeks,  sex can be identified a child.

•    By about 16 to 20 weeks, the pregnant woman can feel the fetus moving. Women who have been pregnant before feeling movements about 2 weeks earlier than women who are pregnant for the first time.

•    By about 24 weeks, The fetus has completely ready for survival outside the uterus.