InGen Pharmaceuticals Inc., Desktop Pharma Inc., and WEN Pharma Inc. are three rival firms who have set up an alliance to conduct research and find a cure for cancer. They have made almost equal contributions to the research, and they also share their expertise with one another. However, the three firms will continue to behave as competitors in markets for other drugs and vaccines. What is this arrangement best referred to as? O takeover O buyout O co-opetition O acquisition