<span>The
correct answer is pharyngeal pouches.</span>
<span>All
chordates for at least some period of their life have pharyngeal pouches (pharyngeal
slits). Those are the openings in the pharynx with the function in the
filter-feeding. Pharyngeal slits are present during the embryonic stages of
tetrapod development. They <span>develop into gill arches (bony fish) and into the jaw and inner ear (terrestrial
animals).</span></span>
The answer to this question is option B for sure.
The protein in the question can be referred to enzymes since its made of protein. The first statement is the answer