Once You Have Offered a Concession,you Should Wait for the Counterparty

Multiple Choice

Once you have offered a concession,you should wait for the counterparty before making further concessions.This conclusion rests on which of the following assumptions?

A) Your counterparty has a very low reservation point.
B) Unilateral concessions decrease the size of the bargaining zone.
C) Your counterparty's offer is not at their reservation point.
D) Your counterparty's first offer is now the anchor point.