To say that transnational cooperation is experiencing a modest Renaissance means two things:
1. At some point in the distant past transnational cooperation was very common. A modest Renaissance
implies that transnational cooperation is starting to become common again but not as common
as it was in the distant past.
2. In the recent past, transnational cooperation was not common. Now it is experience a modest
Renaissance meaning it is becoming more common.
Putting these two piece of information together we get (C):
"Transnational cooperation has in the past been both more common and less common than it is now among United States firms."
As for (A), remember the question is asking us for "information provided in the passage." Nowhere does the passage describe projects that are too big to handle.
(A) is tempting because it describes something that is true in the real world (i.e. some projects are too big for one company to handle), and is commonsensical. Indeed the answer choice may accord with your own experience.
However, the answer must be based solely on the information based in the passage.
Hope that helps
Magoosh Test Prep