Answer:
The answer is option A.
Step-by-step explanation:
In the region where the red-winged blackbirds stop, they are the first birds to be present in the spring.If the red-winged blackbirds are the first to arrive the region during spring the farmers can time the use of the poisoned rice so that it can be used to poison the red-winged blackbirds only, before other migratory birds arrive.