What is the deepest known part of the world's oceans, and the deepest location on the surface of the Earth's crust?

Option C

Marianas Trench is located is in the western Pacific Ocean, to the east of the Mariana Islands. It is about 2,550 kilometres (1,580 mi) long and has a mean width of 69 kilometres (43 miles). It reaches a maximum depth of about 11,034 metres (36,200 ft) at the Challenger Deep, a small slot-shaped valley in its floor, at the southern end.