What is the term for burning fossil fuels and releasing carbon dioxide into the atmosphere?

a)synthesis
b)combustion
c)expulsion

With i really need the correct answer!

The electric field between square plates of a parallel-plate capacitor has magnitude e. the potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. the magnitude of the electric field between the plates is now equal to a)e b)e/4 c)e/2 d)4e e)2e

What sort of waves exhibit the doppler effect?