Definitions of Competition, Cooperation and Collusion: From A&A, p 438, 13.c. “Competition is the interpersonal striving for more of what is scarce and desired – by production, by purchase, by striving for political power, and so on. Cooperation is a joint activity with mutual striving for a common end” From A&A p. 263: "An agreement or coalition that results in smaller output, lowier quality, or higher prices is commonly called a collusion or cartel."
The actual question is from A&A Ch. 13, question 4 (p. 281). The full answer (and it's long) is on p. 454.