Explain how a blocked lacrimal punctum would affect drainage of lacrimal secretions from the surface of the eye

Tears cannot drain normally, causing a watery, irritated or chronically infected eye. Lacrimal secretion (tears) drain through the puncta in the corners of your upper and lower eyelids. The tears then travel through the small canals in the lids (canaliculi) to a lacrimal sac (where the lids are attached to the side of the nose), then down a duct (the nasolacrimal duct) before emptying into your nose.

true is the final answer!

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."