以下哪条信令消息可以判断PScell变更为站间辅站小区变更准备成功?()

以下哪条信令消息可以判断PScell变更为站间辅站小区变更准备成功？()

A.SgNB Addition Request Acknowledge

B.SgNB Modification Request Acknowledge

C.SgNB Change Required

D.SgNB Modification Required

请帮忙给出正确答案和分析，谢谢！