Which statement best describes the role of the constant C in the antiderivative y=F(x)+C obtained from dxdy=f(x)?
a) C translates every antiderivative curve horizontally along the x–axis.
b) C rescales the x–axis, determining the slope of any antiderivative curve.
c) C shifts every antiderivative curve vertically, and its value is fixed by an initial condition.
d) C changes the concavity of an antiderivative but not its position.