The leading causes of impaired, or polluted, surface waters in the United States originate from both point and nonpoint sources. Arrange the causes of pollution from most common to least common according to data from 2012. a. pH changes
b. sedimentation
c. nitrogen and phosphorus
d. hypoxia
e. pesticides
f. pathogensp
g. mercury
h. dissolved metals (excluding mercury)
i. PCBs (industrial pollutant)
1. Most common causes
2. Least common causes

1. Most common causes Mercury, nitrogen and phosphorus, pesticides, dissolved metals (excluding mercury)  and PCBs (industrial pollutant)

2. Least common causes pH changes , sedimentation  and hypoxia.

Explanation:

The most common heavy metals that causes pollution are chromium (Cr), cadmium (Cd), lead (Pb), nickel (Ni), arsenic (As), mercury (Hg), zinc (Zn) and copper (Cu). Nitrogen and phosphorus application pollutes the water due to its leaching nature. The use of pesticides is very common in agriculture that cause more pollution. Pollutant comes from the industries cause water pollution and is responsible for a number of diseases.

the answer is d. made landless peasants that owners of large haciendas

a is the answer i believe.