When a flood threatened their town, two families who had been enemies for years ended up working together to try to save the town from the overflowing river. Generalizing from Sherif's findings, one can reasonably conclude that this act of cooperative behavior may lead to:

A. diffusion of responsibility
B. increased antagonism one the anger has passed
C. an increase in cognitive dissonance
D. a reduced conflict and increased harmony between the two families

D. a reduced conflict and increased harmony between the two families            

Explanation:                    

Cooperative behavior: The term "cooperative behavior" is described as an interaction between two or more than two organizations or individuals that are being directed towards a specific goal which is considered as "mutually beneficial". In other words, it is described as an instance or act related to acting or working with each other for a mutual benefit or purpose.

In the question above, the given families who had been enemies for specific years are now working together to save an overflowing river which leads to reduce conflict and increase harmony between them.

vertical merger is the term used for the joining of two or more firms involved in different stages of producing the same good or services.

explanation:

which sentences ? that question is incomplete