After completing a service incident on a Precision Tower 7920, technician attempts to run ePSA before re-assembling the side cover. However system is not able to power on and displays LED error code of 4-7. What could be the issue

Two students are discussing the flow of electricity. student a says that voltage is a measure of the amount of electron flow in a circuit. student b says that power is the product of voltage and current. which of the following statements is correct? a. only student a is correct b. only student b is correct c. both of the two students are correct d. neither of the two students is correct