Is the function in the table linear or nonlinear and why?

x : -2, 0, 2, 4, 6

y : 5, 10, 15, 20, 25

a) the function is linear because the y-intercept is 0.

b) the function is linear because there is a constant rate of change.

c) the function is linear because all the y values are positive.

d) the function is not linear because there is a negative x value