Which evidence originally supported Hess's idea of seafloor spreading in 1968?

Younger rocks are closer to mid-ocean ridges.

The destruction of crust occurs at deep-sea trenches.

Oceanic rocks are pillow-shaped when formed.

Rocks across the ocean floor have alternating magnetic stripes.

Younger rocks are closer to mid-ocean ridges

Explanation:

Hess was convinced that the continents are moving, and of the things he thought causes their movement was the seafloor spreading. In order to support his idea, Hess was trying to find some evidence about this, and he indeed find it in the sea. The rocks that are at the mid-ocean ridge turned out to be the youngest, and as the distance becomes greater from the mid-ocean ridge, the rocks are becoming older and older. This practically meant that the new crust is forming at the mid-ocean ridges, and the young crust is pushing away the old crust, thus moving the tectonic plates. Lot of scientists accepted the evidence that Hess provided, though there were still some that were very critical of it.

(A) Younger rocks are closer to mid-ocean ridges.