Question

what does the presence of new rock near an oceanic ridge indicate?
there is always a deep - sea trench underneath
there is evidence of seafloor spreading.
they are made from oceanic crust.
they have iron oriented in different directions.

Explanation:

Oceanic ridges are areas where new oceanic crust is formed. Seafloor spreading occurs at these ridges. As magma rises and cools, it forms new rock. The presence of new rock near an oceanic ridge is a key indicator of seafloor spreading. A deep - sea trench is typically found at subduction zones (not always near oceanic ridges). While new rock near oceanic ridges is made from oceanic crust, this statement alone does not explain the significance of the new rock's presence. The orientation of iron in rocks (related to magnetic reversals) is a supporting detail for seafloor spreading theory but not the main indication of what the new rock presence means. So the most appropriate answer is that there is evidence of seafloor spreading.

Answer:

There is evidence of seafloor spreading.