Question

a stack vent is?

a. an extension of a soil or waste stack leading to a header or open air
b. the continuation of a soil or waste stack above tile flood level rim of the highest connected fixture
c. a dedicated vent for a soil or waste stack connected at or below the lowest connected fixture
d. a vent two or more fixtures

Explanation:

A stack vent is defined as the continuation of a soil or waste stack above the flood level rim of the highest connected fixture. This allows for proper venting of the plumbing system.

Answer:

B. The continuation of a soil or waste stack above tile flood level rim of the highest connected fixture