Options are:
a). Continents drifting
b). the environment
c). Animal survival
d). important habitats
e). major threat to health
f). population size
g). an organism's body
h). Something to move

Fact 1: Migration is a type of movement that changes population size. Fact 2: Migration Much of the life of a spiny lobster involves travel. Given the two facts above, a life involving travel is a type of movement that changes what?
Answer:
f).