Final answer:
Functional fixedness is not a problem-solving technique but rather a cognitive bias that can inhibit problem-solving, while the other options listed are acknowledged problem-solving strategies. The correct option is A.
Step-by-step explanation:
The term that is not an example of a problem-solving technique is (A) Functional fixedness. Problem-solving techniques typically involve creative and analytical methods to overcome challenges and find solutions.
Functional fixedness represents a cognitive bias that hinders problem-solving by limiting an individual's ability to use objects in any way other than their intended purpose.
In contrast, trial and error (B), subgoals (C), brainstorming (D), and heuristics (E) are all problem-solving strategies or techniques used to devise workable solutions to various problems.