Which Is the Best Description of a Mid-Ocean Ridge

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

A) thick sequences of folded and faulted sedimentary rocks pushed up 500-1000 metres above the regional seafloor
B) narrow ridges 5-10 kilometres wide, 3-4 kilometres high, and 10-50 kilometres 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) 50-200 metre-wide rough mounds of metal sulphides that encircle the globe continuously for more than 70,000 kilometres