Answer:
Third choice
Explanation:
The following equation above is a linear function.
A linear function is function that only has one-degree. Meaning that x-term cannot have the degree greater than 1.
Therefore, we can cut/rule out the first choice.
Linear Function cannot have a variable as an exponent/degree either. We can rule out the second choice as the equation is an exponential.
Last but not least, we currently have two following choices. Linear Function cannot have the denominator as a variable.
So the answer is the third choice.