Which of the following best explains why oceanic crust is subducted beneath continental crust?
a. oceanic crust is primarily sedimentary rock, which is softer than continental crust and is easily subducted.
b. oceanic crust is denser than continental crust, causing oceanic crust to sink down below continental crust.
c. continental crust is denser than oceanic crust, causing oceanic crust to be deflected down into earth's mantle.
d. continental crust is made of harder metamorphic and sedimentary rocks, which causes oceanic crust to break when the two types of crust collide.