Answer:
Option 2: rare.
Step-by-step explanation:
The word scarce means "insufficient for the demand."
Let's take a look at the definitions of the other options:
- plentiful: producing great quantities; profuse.
- rare: hardly recurring or not available in large quantities.
- useful: high in practicality; for many purposes.
- great: above average in quantity, quality, or expectation.
It is evident that rare comes closest to the definition of scarce.