Which hypothesis explains why continental plates have higher elevations thean oceanic plates

Continental plate is less denser than the oceanic plate so it is floating on the oceanic plate.  

Explanation:

Continental plate is composed of Silicon and Aluminium materials otherwise it is known as SiAl layer, its average density is 3 g/m3. Oceanic plate is composed of Silicon and Magnesium minerals otherwise it is known as SiMa layer and its average density is 5 g/cm3. Both continent and ocean plate lies in the Lithospehere, it extends up to 100 km of the below earth. Temperature will increase if we go beyond every metre in depth.