Which Is the Best Description of a Mid- Ocean Ridge

Which is the best description of a mid- ocean ridge?

A) 50- 200 metre- wide rough mounds of metal sulphides that encircle the globe continuously for more than 70,000 kilometres
B) narrow ridges 5- 10 km wide, 3- 4 kilometres high, and 10- 50 km long with active erupting volcanoes every 1- 2 kilometres of ridge length
C) 1000 to 4000 kilometre wide, block faulted regions of sparsely sedimented, basaltic seafloor raised 2- 3 kilometres above the regional abyssal plains
D) thick sequences of folded and faulted sedimentary rocks pushed up 500- 1000 metres above the regional seafloor