Final answer:
The correct answer to the candle problem illustrating functional fixedness is 'c' the box is empty, which enables people to repurpose it and solve the problem. The correct answer is option: c. the box is empty.
Step-by-step explanation:
People are more likely to solve the candle problem by overcoming functional fixedness if the box is empty. This is because an empty box more readily suggests itself as a support for the candle, rather than when it is full of tacks, viewed only as a container. The term 'functional fixedness' refers to a cognitive bias that limits a person to using an object only in the way it is traditionally used. The candle problem, developed by Duncker in 1945, is a classic example used to study this concept.
The correct option is 'c' the box is empty, signifying that the lack of additional items can prompt a person to think outside the box (literally and figuratively) and repurpose the object for an unintended use, which is key in solving problems where traditional uses do not apply.