Question

1. where is the youngest rock on the ocean floor located?

at mid - ocean ridges
at the edge of continents
very far away from the mid - ocean ridge
at the trenches

Explanation:

Mid-ocean ridges are seafloor spreading centers where new oceanic crust is continuously formed by magma rising from the mantle. As new rock is created here, it is the youngest on the ocean floor; rocks get older as they move away from the ridges toward trenches or continent edges.

Answer:

at mid-ocean ridges