Which of the following is most likely to happen if a person drinks untreated water from a road side ditch

That person might get  allergies to any mold and pollen that have fallen in the water. The person might contract an upper respiratory tract infection from viruses in the water.

Explanation:

Option B

Two calcified valves: dorsal and ventral

Explanation:

Brachiopods are animals that have hard shells on the upper and lower surfaces, unlike the left and right arrangement in molluscs.

The dorsal and ventral arrangement of shells in brachiopods is their key distinguishing feature from the bivalve molluscs and other animals.

This makes option B the correct answer