Final answer:
Voltage indicates the amount of energy given to each coulomb of charge by a battery; therefore, the correct answer is D, representing the electrical potential energy per unit charge.
Step-by-step explanation:
The student's question pertains to what a battery's "voltage" indicates. Option D is the correct answer: Voltage is the amount of energy it gives to each coulomb of electrical charge. In physics, particularly when discussing a battery like the lead-acid battery, an energy of 2 electron volts (eV) is given to each electron sent to the anode. Essentially, voltage is defined as the electrical potential energy (PE) per unit charge (q), or V = PE/q. An electron volt is the amount of energy conferred to a single electron by a voltage of one volt. The distinct molecular reactions producing this energy result in the specific voltage of a battery.