Which of the following can be natural sources of water pollution?
a. volcanic activity
b. earthquakes
c. algae blooms
d. all of the above

All of the above choices can be natural sources of water pollution. Volcanic activity could cause water pollution by its debris of magma, smoke, ashes, rocks, etc. Earthquakes could displace any material from one place to another. Algae blooms, when many, is detrimental to water as well.

one part of the electromagnetic spectrum that arrives on earth as solar radiation from the sun is the visible spectrum. wavelengths of the visible spectrum combine to form what we refer to as

answer - d) ultraviolet radiation.

violet /   380–450 nm / 668–789 thz

violet is number 1 in the chart of visible light.