Which of the following is caused by pollutants from farm runoff, feedlots, or septic tanks?
question 2 options:

1) increased fecal coliform

2) low dissolved oxygen

3) temperatures greater than 45 c

4) ph below 6.5

The correct answer is option 1, that is, increased fecal coliform.

Explanation:

A bacterial strain that can be witnessed in colonies in the digestive tract of animals and humans is known as the fecal coliform. It discharges from the body with the feces. It is possible that it can be found in the farm runoff as it can be a constituent of the cattle dung based manure that can be used in farming.  

It can also be found in the feedlot due to the daily discharge of dung by the cattle there. In the septic tank, the animal or human fecal matter will demonstrate the colony of the coliform bacteria. Thus, if the liquid or solid matter from any of these discharges go within the freshwater body it will possibly result in pollution due to the existence of fecal coliform.  

3 1/4 %

explanation:

the answer is c.the valence of the atoms combine .