A landslide is incorrect because when the ground shakes it can sometime cause the ground to shift making it unstable. When this happens the dirts becomes loose and starts the landslide.
A tsunami is incorrect because the vibration caused by the earth quake causes the earth to vertically displace causing the tsunami.
And the wildfires occur because the vibration of the tectonic plates can cause gas lines to leak casing a fire the spreads very quickly.
A and D are likely answers, as fur trading was a mostly French ordeal, and 'both' doesn't imply difference. The French traded with natives and didn't completely colonize, so it's a 50/50 bet between those two.
