甲与乙离婚并达成协议：婚生男孩丙(3岁)由乙(女方)抚养，如双方中一方再婚，丙则由另一方抚养，后乙在丙6岁时再婚，甲去乙家接丙回去抚养，乙不允。一次甲从幼儿园将丙接回，并电话告知乙，为此，双方发生争执，诉至法院。下列有关论述正确的有哪些( )

A．甲、乙均为丙的监护人

B．乙的行为是违约行为，受合同法调整

C．甲欲行使对丙的抚养权，应通过诉讼程序解决

D．甲、乙的协议违反了法律

Tell me ________ how it came about that you were 20 minutes late for class. You needn’t go into details.

A．in advance

B．in vain

C．in total

D．in brief