Mt. redoubt’s seismic activity is due to the interaction of which two tectonic plates

Correct answer is: Due to interaction between Pacific and North American plate.

Explanation:

Mountain Redoubt is located in south Alaska. Mentioned mountain is in the vicinity of convergent plate boundary between North American and Pacific plate.

Convergent boundary means that those plates are colliding. One plate always slides beneath another, and in this case Pacific plate slides beneath North American. Area of collision is known as subduction zone.

Pacific plate is oceanic plate, and North American is continental plate. Oceanic plates always slides beneath continental ones. Reason for that is due to their density. Oceanic plates are denser, so they go under continental ones.

Pacific and North American plate interaction is typicall oceanic-continetal boundary where earthquakes (seismic activity) and active volcanoes are common. Some of the strongest earthquakes happened in this area. That was in 1964 in Prince William Sound in the south coast of Alaska. Magnitude was 9.2M, second strongest quake ever recorded in world's history.