Final answer:
The two different voltages provided by a PCI slot are 3.3 volts and 5 volts, which is important for the compatibility of hardware components with the computer system.
Step-by-step explanation:
The two different voltages that a PCI (Peripheral Component Interconnect) slot can provide are 3.3 volts and 5 volts. The correct answer to this question is A) 5V and 12V. PCI slots are key components in computers that allow for the addition of expansion cards to provide new functionalities or additional resources to the computer system. These slots provide power to the expansion cards as well as enabling communication between the cards and the computer's central processing unit. The voltage level provided by a PCI slot is important for the compatibility of hardware components. Older expansion cards typically required 5 volts, while newer cards often use 3.3 volts. Some slots are keyed to accept only one type of voltage, whereas others may support both, determined by the design of the slot connectors and the corresponding card notches.