22. (1) when oceanic and continental material converge? a. the older plate is subducted b. the denser material is subducted c. a marine trench does not form d. all of the above

b. The denser material is subducted

Explanation:

During a continental-oceanic convergence, a subduction zone forms. Subduction zones are depressions between the colliding margins of two plates. Here, the oceanic plate which is known to be more denser due to the nature of it materials goes beneath the continental plate which is lighter. It continues to go further deeper into the asthenosphere until partial melting develops.

Density contrast is what causes subduction between two plate margins such as continental and oceanic plates.