It is needed at least one more piece of information.
If you call k the ratio a'b' / ab , the addtional information may be tha cb' has the same ratio to cb or that ca' has the same ratio to ca.
It migh also be that the angle at the vertex C has not changed.
I just took the test the answer is 9 cm.
Answer: OPTION A.
Step-by-step explanation:
Given the following function:

You know that it represents the the height of the ball (in meters) when it is a distance "x" meters away from Rowan.
Since it is a Quadratic function its graph is parabola.
So, the maximum point of the graph modeling the height of the ball is the Vertex of the parabola.
You can find the x-coordinate of the Vertex with this formula:

In this case:

Then, substituting values, you get:

Finally, substitute the value of "x" into the function in order to get the y-coordinate of the Vertex:
Therefore, you can conclude that:
<em> The maximum height of the ball is 0.75 of a meter, which occurs when it is approximately 1 meter away from Rowan.</em>