Requirements for a Hurricane to Develop Include All but Which

Requirements for a hurricane to develop include all but which of the following?

A) Seawater with a temperature of at least 27°C in the upper 60 m of the ocean
B) Air must be unstable,warm,and humid
C) Weak upper-level winds,preferably blowing in the same direction the developing storm is moving
D) Tornado serving as triggering mechanism,spreading out and slowing as storm grows
E) All of the choices are required for a hurricane to form