Bob Is Head of His Department at Work

Bob is head of his department at work. Lately, he's noticed that the older workers and the younger workers have separated into two groups (older versus younger) , and the two groups are becoming increasingly hostile toward one another. Based on the famous study by Muzafer Sherif, what should Bob do to reduce conflict and hostility between the older and younger workers?

A) Bob should have a public forum where the two groups can air their grievances.
B) Bob should give them a project that will require the two groups to work together toward a common goal.
C) Bob should give them a project that will allow the two groups to compete against one another.
D) Bob should try to keep the two groups isolated from one another in order to minimize the opportunity for conflict.