Which Is True of Earth's Atmosphere

Multiple Choice

Which is true of Earth's atmosphere?

A) it is the sum of all the exhalations and inhalations of animals on Earth.
B) we consider the top of the atmosphere to be about 10 km from Earth.
C) it lets light through,but blocks out all other forms of radiation.
D) its temperatures range from -90°C to 1200°C.
E) The principle substance is air,a mixture of oxygen and argon gas.