Mutations result from an error in DNA replication, should it be from an alien source (like radiation) or simply a mistake in replication.
Migration of organisms to a new population would alter the DNA by adding new genes, but it would not mutate them.
B) Physiological because C is relating to the inside of the organism, A is relating to the forming part of a building or another item and D is reacting to their physical surroundings, so the only other answer would have to be B because in physiological in animals and humans alike, they change something of their physical self's to attain to the environment around them.
Briefly, one can categorize the 3 types of boundaries as so: At convergent boundaries, the two tectonic plates are coming closer to each other; at divergent boundaries they are increasing they move away from each other and at transform boundaries the plates are moving parallel to their boundary. Based on this, all boundaries will be divergent boundaries.