Question

when are new ocean ridges and areas of seafloor formed?
when tectonic plates are stable
when tectonic plates move apart
when tectonic plates slide against each other
when tectonic plates move together

Explanation:

New ocean ridges and seafloor areas form at divergent plate boundaries where tectonic plates move apart. Magma rises up to fill the gap, solidifies, and creates new crust.

Answer:

when tectonic plates move apart