I think the correct answer is the first option. The key features of chordates would be notochord, dorsal tubular nerve cord, pharyngeal pouches, and a tail. These features appears in some period of their lives. They are deutorostomes where the anus would be formed first before the mouth.
Answer:
Both the initial and final substances are composed of atoms because all matter is composed of atoms.
Gastric analysis can be used to measure the amount of hydrochloric acid under baseline and stimulated conditions.
