Do you know what that shape is?!

What is the effect on the graph of the parent function f(x) = x when f(x) is replaced with 3f(x)? a) shifts the line 3 units up b) shifts the line 3 units down c) increases the slope of the line by a factor of 3 d) decreases the slope of the line by a factor of 3

Can somebody me out with this question

25 ! the line of best fit is h = 5a + 86. predict the height at age 16.