Answer: 
If f (8) = 19, then a test-taker receives 19 points for answering 8 questions in the section correctly.
Explanation: 
We are told that the function f(x) outputs points on a section on an exam given x the number of questions answered correctly. This means if put in in x (the number of correct answers) f(x) will take the value of the number of points scored. 
Hence, x = 8 means 8 questions were answered correctly and f (8) = 19 means that 19 points were earned. 
Thus, the correct wording is 
"If f (8) = 19, then a test-taker receives 19 points for answering 8 questions in the section correctly."