Subduction zones mainly affect people who are living in

The correct answer is - Pacific outskirts.

The people that live in the outskirts of the Pacific Ocean are the ones that are the most affected by the subduction zones. This is because the Pacific plate is an oceanic plate, and pretty much on all sides, it is surrounded by continental plates. Because the movement of the plates is in a amanner where it puts the Pacific plate to be in collision with all its surrounding plates, it is shrinking in size, because it is subducting on all sides.

The subduction zones appear in close proximity to the plate boundaries, which happens to be very close to the coastal regions where lot of people live. Because of the subduction, there's lot of geologic activity in the form of volcanic activity, earthquakes, tsunamis, which all are able to make a lot of damage.