Research by Van Vugt and Samuelson (1999),in Which Water Meters

Research by Van Vugt and Samuelson (1999) ,in which water meters were installed in houses in one community,but not in another,suggests that when people can monitor their own use of a scarce common resource,they may use less of that resource because

A) using less helps them save money.
B) they become concerned for the collective good.
C) people become competitive and vie to use less.
D) they feel as if 'big brother' in the form of the utility company is watching them.
E) using less stops them feeling guilty all the time.