Which statement best explains how an embryo can produce a different type of hemoglobin from that of an infant, child, or adult?

a) The embryo's genetic code changes after birth, leading to the production of a different type of hemoglobin.
b) Hemoglobin production is controlled by different genes during embryonic development compared to later stages of life.
c) Embryonic stem cells have unique properties that enable them to synthesize a distinct form of hemoglobin.
d) Hemoglobin undergoes structural modifications as the embryo matures, resulting in a different molecular composition.