Could you help me figure this out?

The cilia serve to transport dust and other foreign particles, trapped inmucous, to the back of the nasal cavity and to the pharynx. There the mucus iseither coughed out, or swallowed and digested by powerful stomach acids. After passing through the nasal cavity, the air flows down the pharynx to thelarynx.

what image you forgot to include it.

answer; i believe that the correct answer is(d) nondisjunction during meiosis;