Select the correct answer.
Martina creates the graph of function g by applying a transformation to function f:

f(x) = 4x − 2
g(x) = 4x + 7

Which transformation did Martina apply?

A.
a horizontal shift of 9 units left
B.
a vertical shift of 9 units down
C.
a horizontal shift of 9 units right
D.
a vertical shift of 9 units up