Question

which type of crust is generally the youngest? continental crust asthenospheric crust oceanic crust

Explanation:

Oceanic crust is formed at mid - ocean ridges through seafloor spreading and is continuously being created. Continental crust is much older as it has been around for long periods and has accumulated over time. The asthenosphere is part of the mantle, not a type of crust. So oceanic crust is generally the youngest.

Answer:

oceanic crust