The correct answer is D. Scarcity.
A dearth is a lack of something, especially something that is needed or desirable. It can also mean a period of time when something is scarce.
Decrease, loss, and reduction all mean a decrease in something. However, they do not necessarily mean that there is a lack of something. For example, the number of people living in a city may decrease, but there may still be a large number of people living in the city.
Scarcity, on the other hand, specifically means a lack of something. It can be used to describe a lack of anything, from food to water to money.
Here are some examples of how the word dearth can be used in a sentence:
- There is a dearth of affordable housing in the city.
- The drought has caused a dearth of water in the region.
- The company is facing a dearth of qualified employees.
I hope this helps!