Which translation maps the vertex of the graph of the function f(x) = x2 onto the vertex of the function g(x) = x2 + 2x +1?
A.right 1 unit
B.left 1 unit
C.right 2 units
D.left 2 units
A.right 1 unit
B.left 1 unit
C.right 2 units
D.left 2 units