Answer:
c. countifs
Step-by-step explanation:
The key word in the question is "following functions automatically counts cells". So, you can already eliminate answer D.
With COUNTIFS, you can specify multiple criteria based on as many range for consideration.
For example, count this cell, if the value in column D is bigger than 23 AND if the date in column E is lower than June 30, 2019.
It gives great power of filter and calculation to your sheet, almost as good as a database.