Each characteristic of an organism. A.
DNA
B.
Trait
C.
Complementary Bases
D.
gene

for me it's

Explanation:

traits on my opinion

The correct answer is trait

wadadadwawadwdwdaddwawdwad

poor water quality affects most estuarine organisms, including commercially important fish and shellfish. the pollutants that have the greatest impact on the health of estuaries include toxic substances like chemicals and heavy metals, nutrient pollution (or eutrophication), and pathogens such as bacteria or viruses.