Which of the following is true of oceanic crust?

a) It makes up 71% of the earth's crust.

b) It makes up 29% of the earth's crust.

c) It averages 2,000 feet above sea level.

d) It is the type of crust between Alaska and Siberia.

A) it takes up 71% of the earth's crust.

A. It take up 71% of the earth's crust.

Explanation:

The oceanic crust makes about more than 70 percent of the oceanic landmass, having a thickness of 25 to 70 kilometers thick. Its the oldest of the crust on earth. Having an average density of 2,7 g/cm, primarily being composed of denser rocks like basalt and gabbro from below. Mostly it's basaltic, from here all sorts of rocks are recycled to the outer land surface of the earth. Accounting for nearly 60% of the global slab of plates. Apart from this, the seafloor is covered with volcanic necks, trenches and deep-seated volcanoes that produce magma and the oceanic floor is composed of layers of rocks that date back to the various epi, meso, bathy, and abyssopelagic divisions.