Final answer:
The problem that illustrates functional fixedness is the candle problem. This cognitive bias prevents someone from using an object in ways other than its conventional use, as shown in Duncker's experiment and further evidenced by studies involving both industrialized and non-industrialized cultures. The anchoring bias is when one becomes fixated on a single aspect of a situation.
Step-by-step explanation:
The problem that illustrates functional fixedness is a) the candle problem. Functional fixedness is a cognitive bias where a person is unable to think of alternative uses for an object other than its traditional use. This concept was a key finding from Duncker's experiment, where participants struggled to see the box of thumbtacks as anything other than a container, inhibiting their ability to solve the presented problem. This problem-solving difficulty was similarly seen when NASA engineers during the Apollo 13 mission had to think creatively and go beyond the conventional uses of available tools to save the astronauts.
Moreover, research has shown that functional fixedness is not limited to industrialized cultures; it's experienced worldwide, indicating the widespread effect of this cognitive bias on problem-solving. Researchers German and Barrett in 2005 found that the Shuar group from Ecuador, like those in industrialized nations, displayed functional fixedness when asked to use objects in unconventional ways.
Answering a related question, the type of bias that involves becoming fixated on a single trait of a problem is known as anchoring bias.