Final answer:
Scarcity is the condition of having to choose among alternatives when faced with a lack of volunteers.
Step-by-step explanation:
Scarcity is the condition of having to choose among alternatives when faced with a paucity of volunteers. It means that there is a lack or shortage of volunteers. Scarcity can be defined as the opposite of abundance, which is having a large amount of something. In this case, the correct synonym for scarcity is b) scarcity.