Answer:
The difference quotient of f is 8. Option C
Step-by-step explanation:
Difference Quotient
Given a function f(x), the difference quotient is defined as

The function provided in the question is

Find f(x+h) by substituting x by x+h:


Now compute:

Operating:

Simplifying:

d=8
A. Incorrect.
This choice is different from the answer.
B. Incorrect.
This choice is different from the answer.
C. Is correct
The difference quotient is 8 as explained above.
D. Incorrect.
This choice is different from the answer.