瞳孔 どうこう括約 かつやく すじでしょう
dōkō katsu yakusujideshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of 瞳孔括約筋

1. Probably the pupillary sphincter.

Polite
Presumptive
Conjecture
Anatomy