Kate::
Conclusion: Decline of Tennessee warbler is due to loss of tree cover South American coffee plantations.

Scott::
Conclusion: Warbler's decline is due to the declining population of the spruce budworm.
Premise: Spruce budworm is warbler's favorite prey in North America

Assumption 1: Warblers do not have another major food source other than budworm
Assumption 2: decline in favorite food sources will cause Warblers to starve and decline in number.
Assumption 3: Dense forest cover during migration is not important for Warbler's survival.

A. The numbers of the Baltimore oriole, a songbird that does not eat budworms but is as dependent on South American coffee plantations as is the Tennessee warbler, are declining
Strengthens conclusion 1 by giving an example of another species affected for same reason but the parameter important for conclusion 2 is missing and makes the 2nd conclusion weak. Correct option

B. The spruce budworm population has dropped because of a disease that can infect budworms but not Tennessee warblers
Does not affect the 2nd conclusion

C. The drop in the population of the spruce budworm is expected to only be temporary
Irrelevant & does not affect 2nd conclusion

D. Many Tennessee warblers have begun migrating in the fall to places other than traditional coffee plantations
Irrelevant & does not affect 2nd conclusion. Does not talk about decline in number. Out of scope.

E. Although many North American songbirds have declined in numbers, no other species has experienced as great a decline as has the Tennessee warbler
Irrelevant & does not affect 2nd conclusion

Answer: A