Critical Reasoning

The red-eyed cowbird breeds by parasitizing the nests of orioles, among other birds. The cowbird lays its eggs in the orioles' nests while the female orioles are out searching for food. The cowbird has evolved certain traits and behaviors to ensure the success of its deception: It throws one oriole egg out of the nest for every one of its own eggs that it lays therein, and it has evolved an egg coloration similar to that of the oriole. An oriole whose nest has thus been parasitized will subsequently incubate and rear the cowbird chick, unaware of the cowbird's ploy.

Which of the following conclusions can most properly be drawn from the information above?

1. The stability of oriole populations is threatened by the behavior of red-eyed cowbirds.
2. The oriole does not possess any numeric ability.
3. The stability of red-eyed cowbird populations depends on the proximity of nesting orioles.
4. The red-eyed cowbird's behavior is not learned.
5. Scientists are unable to distinguish between a red-eyed cowbird egg and an oriole egg based solely on visual examination.

IMO:D

please explain

First, determine the scope of premise.

1. Cowbird behavior (lay egg, egg with similar color as oriole's egg, how cowbird can deceive the orioles..)
2. Orioles behavior

Now, examine the answer choice
A. Talk about population, out of scope
B. Do not talk about numeric ability => out of scope
C. Premise do not talk about proximity. It just talked about how cowbird lay its eggs while orioles forage for food. => out of scope
D. Behavior of cowbird is not learn => in scope, let's try to prove this answer choice. Yes, it is. The young cowbirds that is raised by orioles cannot meet their real mother? How they can meet their mother? The behavior of this bird is the instinct, and it is not learned.
E. Do not talk about scientist => out of scope.

Beside use scope to narrow your choices, you have to be able to prove the choices that are in scope which choice is the best one.

Hope that helps