Final answer:
Set 2 containing the terms 'efficient', 'improved', and 'user-friendly' indicates an ambiguous requirement as these terms are subjective and lack specific, measurable criteria.
Step-by-step explanation:
When discussing ambiguous requirements, the goal is to identify terms that are vague and subject to interpretation, as they can lead to misunderstandings and difficulties in measuring success or completion. Among the provided sets of terms, Set 2 which includes efficient, improved, and user-friendly indicates an ambiguous requirement. All three terms are subjective and lack specific definitions or quantifiable metrics.
For example, efficiency could mean different things in different contexts—it could refer to speed, resource usage, or cost-effectiveness, among other things. Similarly, improved is a relative term that requires a baseline to determine the degree of improvement. Furthermore, user-friendly is an attribute that can vary significantly based on the user's experience, preferences, and expectations.