A Water Tank Is Constructed in the Shape of a Sphere

Multiple Choice

A water tank is constructed in the shape of a sphere seated atop a circular cylinder.If water is being pumped into the tank at a constant rate, let $h(t)$ be the height of the water as a function of time.Which of the following is true at the point where $h(t) =$ b?

A) The second derivative doesn't exist
B) There is an inflection point
C) The slope is infinite
D) None of the above