Explanation:

All three listed factors are drivers for the formation of ocean gyres:

Westerly-driven ocean currents in the trade winds: These are key drivers in the equatorial regions, influencing the movement of water and contributing to the formation of gyres.

Easterly-driven ocean currents in the Westerlies: These currents, found at higher latitudes, play a significant role in the movement of water in gyres.

Deflection of the ocean currents by the continents: The physical presence of continents affects ocean current paths, contributing to the circular motion of water in gyres.

Hence, all three factors are involved in the formation and maintenance of oceanic gyres.