Answer
The trochophore, or the free-living larval form, is a characteristic of both annelids and mollusks and is a clue that annelids and mollusks are closely related to one another.
Work Step by Step
The trochophore, or the free-living larval form, is a characteristic of both annelids and mollusks and is a clue that annelids and mollusks are closely related to one another.