The house that surrounds me while I sleep is built on undermined ground; far beneath my bed, the floor, the house’s foundations, the stopes and passages of gold mines have hollowed the rock, and when some face trembles, detaches, and falls, three thousand feet below, the whole house shifts slightly, bringing uneasy strain to the balance and counterbalance of brick, cement, wood, and glass that hold it as a structure around me.
Choose the best synonym for the word undermined as it is used in this excerpt from Nadine Gordimer’s “Once Upon a Time.”
bolstered
broken
challenged
weakened