What is the biotic index ? nc caroline water quality

answer: biotic index is a scale for showing the quality of an environment by indicating the types of organisms present in it. it is often used to assess the quality of water in rivers. it is measured from 1 to 10 and corresponds to the four basic water quality. but that finding is highly misleading and does a disservice to one of the nation's best municipal water systems. raleigh's tap water is perfectly safe to drink and, according to the north carolina american water works association, one of the “best tasting” in north carolina.

the answer is c) abandoned properties that are contaminated with hazardous materials.

answer; i believe the correct answer is ( proteins );