The correct option is B f(c)
We know that, A function f(x) posses maxima at any point x if f′(x)=0
i.e. tangent is parallel to x-axis.
It is clear from graph that f′(c)=0, also the graph's nature is concave downward i.e. f′′(x)<0
Hence f(c) is the maximum vale of the given function.