Why does phosphate act as an environmental contaminant?

Too much phosphorus in the water causes algae to grow faster than ecosystems can handle. Large growths of algae are called algal blooms and they can severely reduce or eliminate oxygen in the water, leading to illnesses in fish and the death of large numbers of fish.

Explanation

Futhermore, with a loss of fish the whole ecosystem will be upset and will be in need of serious recovery.

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.

i'm pretty sure it is letter c.) car