Answer:
The correct option is A.
Explanation:
The vertex from of a parabola is

Where, (h,k) is vertex of the parabola and a is a Constant.
From the given graph it is clear that the vertex of the parabola is (1,0) and the y-intercept is (0,1).
The vertex of the parabola is (1,0). Put h=1 and k=0 in the above equation.

... (1)
The graph passing through (0,1).


Put a=1 in equation (1) to find the equation of parabola is


Therefore option A is correct.