A Boy Is Standing on a Flat Field and Tosses $f(x)=-4 x^{2}+8 x$

Multiple Choice

A boy is standing on a flat field and tosses his ball toward a second boy standing at the other end of the field. The path of the ball is a parabola, and the equation of the path is $f(x) =-4 x^{2}+8 x$ . Based on this information, answer the question.
-What is the highest the ball will be above the flat field and for what value of $x$ ?

A) Highest height $=4$ when $x=2$
B) Highest height $=4$ when $x=1$
C) Cannot determine without additional information
D) None of the above