Why Is Pacific Salmon Movement into Freshwater Streams Considered Migration

Multiple Choice

Why is Pacific salmon movement into freshwater streams considered migration if the salmon die at the head of the stream and never return to the ocean?

A) It is not considered migration but immigration.
B) Migration is a one-way movement.
C) Because their offspring return to the ocean,the entire population participates in the migratory event via different life stages.
D) Most male adult fish survive reproduction and return to the ocean.