The correct answer is: D. Video controller
A field-replaceable unit (FRU) is a component of a system that can be removed and replaced without the need to return the entire system to the manufacturer for repair. FRUs are typically used in computer systems, but they can also be found in other types of equipment, such as cars and appliances.
The system ROM, power supply, and system chassis are all examples of FRUs. The video controller, on the other hand, is not typically a field-replaceable unit. This is because the video controller is often integrated into the motherboard, which is a major component of the system that is not easily removed or replaced.
In some cases, it may be possible to replace the video controller on a motherboard. However, this is typically a complex and time-consuming process that is best left to experienced technicians. If you are experiencing problems with your video controller, it is usually best to contact the manufacturer of your system for assistance.