Why can performance remain limited if the Central Processing Unit is fast but the data bus is very narrow?

Correct answer: Because less data can be transferred at one time

The governing concept is bus bandwidth. A data bus provides the path through which data moves between the processor, memory and other components. A narrow bus carries fewer bits in one transfer cycle, so the fast CPU may have to wait for more transfer cycles before receiving or sending all required data. Thus option B is correct. Monitor brightness, printer speed and the number of keyboard keys do not determine the width of the data path.