The Deepest Parts of Earth's Oceans Are

The deepest parts of Earth's oceans are:

A) subduction zones, where one tectonic plate is flowing under an adjacent plate.
B) at the two poles, near the ends of the spin axis, where tidal distortion from the Moon and Sun is least.
C) in the centers of the oceans, where deep and fast ocean currents such as the Gulf Stream have scooped out the troughs.
D) where large asteroids or planetoids have impacted in the past and have produced deep craters.