The twin brothers showed great ________ to their elder sister, who had acted as sole parent to them since their parents died during the American Civil War.
句意：这对双胞胎兄弟很爱姐姐，因为父母在美国内战中身亡，姐姐一直扮演单亲妈妈的角色。 allegiance忠诚。devotion热爱。compliance服从。subjection顺从。因此答案选B。