Scientists have observed that when oceanic plates and continental plates collide, the oceanic plate is driven under the continental plates. The MOST LIKELY reason for this phenomenon is - the convection currents in the mantle.
the convection currents in the mantle.

water applies a downward force on the oceanic plate
water applies a downward force on the oceanic plate

the oceanic plate is more dense than the continental plate.
the oceanic plate is more dense than the continental plate.

the continental plate is wider than the oceanic plate.