Answer:
Second Choice.
Step-by-step explanation:
[tex]y = mx + b[/tex]
That is the linear function. Any coefficients with higher degrees won't be considered as a linear function.
So we can cut out the first and last choice.
Then we have only two choices which are
[tex]y = \frac{x}{2} - 5 \\ y = \frac{2}{x} + 3[/tex]
The second equation is called Rational Function where a variable is a denominator.
Therefore, the correct answer is second choice.