问题：

[单选] How are STP timers and state transitions affected when a topology change occurs in an STP environment？（）

A . All ports will temporarily transition to the learning state for a period equal to the max age timer plus the forward delay interval.
B . All ports will transition temporarily to the learning state for a period equal to the forward delay interval.
C . The default aging time for MAC address entries will be reduced for a period of the max age timer plus the forward delay interval.
D . The default hello time for configuration BDPUs will be reduced for the period of the max age timer.