Answer:
C It is a linear function because there is a constant rate of change in both the input and output.
Step-by-step explanation:
With the values, you can see that the Y value is always 2.5 times the value of X. That's a constant rate of change.
Answers A and B make no sense, because the fact that the input or output values are increasing or decreasing have no impact to determine if a function is linear or not, can be linear or non-linear in all cases.
Answer D gives the definition of a linear function, but applies it to a non-linear function.