Answer:


Step-by-step explanation:
A linear function is one that has the following form:

Where m corresponds to the slope (degree of inclination of the line), and b the cut point on the y-axis.
Now we search among the options those that correspond to the linear function formula
a.

Is a linear function where

b.

Is not a linear function equation since the variable x is in the denominator
c.
Is a linear function where

d.

Is not a linear function since the variable x is squared.