A student divided \(f(x) = 3x^3+8x^2+5x-4\) by \(x+2\) and found the remainder was \(r=-6\). Based on the remainder theorem, what can be concluded about \(f(x)\)?
a) The point \((-2,-6)\) lies on the graph of \(f(x)\).
b) The function \(f(x)=3x^3+8x^2+5x-4\) has a zero at \(-6\).
c) The function \(f(x)=3x^3+8x^2+5x-4\) has a zero at \(-2\).
d) The y-intercept of the graph of \(f(x)\) is \(-6\).
