Rome Set a Precedent for Treating Its Vanquished Foes After

Rome set a precedent for treating its vanquished foes after forming the Roman Confederation by

A) forcing slave labor on the populace of the defeated cities.
B) offering its most favored allies full Roman citizenship, thus giving them a stake in successful Roman expansion.
C) slaughtering the citizens wholesale and selling the rest to pirates.
D) confiscating all the property of defeated peoples.
E) creating for the first time the citizen category of "plebian".