Final answer:
Sea-floor sediment becomes thicker near the shore, not with increasing distance from a mid-ocean ridge.
Step-by-step explanation:
The statement that sea-floor sediment becomes thicker with increasing distance from a mid-ocean ridge is incorrect.
Sea-floor sediment is actually thickest near the shore where it comes off the continents in rivers and wind currents. As you move further away from the shore and towards the mid-ocean ridge, the sediment layer becomes thinner.
For example, in the Gulf of Alaska, the sediment layer is up to 1.5 km thick, but as you move towards the mid-ocean ridge, the sediment layer becomes thinner.