The correct answer is: D. +3.3 volts
A Pentium system uses +3.3 volts to power its components. This voltage is supplied by the power supply unit (PSU) and is used to power the CPU, memory, and other components.
The other options are incorrect because they are not the correct voltage for a Pentium system. Option A, +12 volts, is the voltage used to power the hard drive and other peripherals. Option B, +5 volts, is the voltage used to power the motherboard and other components. Option C, +8 volts, is not a standard voltage used in computers.
I hope this helps! Let me know if you have any other questions.