Batteries always use direct current. That eliminates A and C. The other part of the answers is just asking what direct/alternating means. Alternating currents change directions moving one way then another. Direct current only moves in one direction. Therefore, the answer is D, since the current is direct and direct currents move in one direction.
First of all, I is proportional V according to the Ohm's Law. R is merely a constant you need to obtain an equation. However, it is true that R changes with temperature and pressure, therefore Ohm's Law is only applicable in an invariable environment. Also this constant R is different for different materials.
So, do not get confused.
Ohm's law is not a universal law, please remember that as well. Some materials do not follow it and we call them non-ohmic conductors. I hope I helped! ^-^
Answer:
He did not multiply the chlorine and oxygen atoms by the coefficient 4
Explanation: