Answer:
A. It uses less energy to make something from recycled materials than from new materials.
Explanation:
I think it is this one because it is the only one that is not harmful to the environment. Also, I took the test a few minutes ago.
If the field strength between the plates is 9 volts per cm, then over a path of 1/2cm parallel to the field, the potential changes by (1/2) x (9 volts) = 4.5 volts.