Answer:
First trimester
Explanation:
During the first trimester, the organs of the fetus will begin to develop, the spine, the facial features - nasal pits, optic vesicles, buccal orifice -, the legs, arms and fingers. They will also begin to develop the respiratory system and the digestive system, as well as the cord that serves to feed the creature - through the mother - provide oxygen and eliminate waste and carbon dioxide during pregnancy. It is the right time to perform the first ultrasound since the heart already beats - although it does so in a soft and delicate way that we can not perceive - and the embryo is already moving.
