Answer:
C. y = 3/x + 1
Step-by-step explanation:
A linear function is, well, a line. The line goes on indefinitely without a stopping point.
In one of these functions, there is a line with a stopping point.
The function y = 3/x + 1 has a point that does not have a value, which is 0. 0 cannot be a value in a denominator. All of the other functions can be expressed at all values.
Graphical proof is attached. The function in green has a discontinuity at x = 0 and therefore is not linear.
