The need to construct a scale of preference is necessitated by____________

1. Analyze the question The question asks what makes it necessary to draw up a scale of preference. A scale of preference is a list of a person's wants arranged in order of importance, from the most urgent to the least urgent.

2. Explain the concept Human wants are unlimited, but the resources used to satisfy them (money, time, materials) are limited. This is scarcity. Because of scarcity, we cannot satisfy every want, so we must choose which wants to satisfy first. The scale of preference is the tool that helps us make that choice. Choosing one want means giving up another, and the one given up is the opportunity cost.

3. Work through the options

• A. Scarcity and the need for choice. This is the most complete answer. It gives both the cause (scarcity) and the reason the scale is needed (we must choose).
• B. The need to satisfy wants. Wants exist whether or not there is scarcity. If there were no scarcity, we could satisfy all of them and would need no ranking.
• C. Non-availability of factors of production. This is too narrow. It also suggests resources are completely absent, when the real problem is that they are limited.
• D. Scarcity of resources. This is partly correct, since scarcity is the root cause. But it leaves out the choice that the scale of preference exists to guide. Option A includes scarcity and adds choice.

4. Answer Scarcity forces us to choose, and choosing requires ranking our wants.

5. Exam tip Remember the chain Unlimited wants → Scarcity → Choice → Scale of preference → Opportunity cost. When two options both mention scarcity, pick the one that also mentions choice, because that is what a scale of preference deals with.