单选题
By signing the lease you made a(n) ______ to pay $ 300 a month rent.
【正确答案】
B
【答案解析】解析：commitment(to)n.保证：承担的义务(如：I must honour my commitments to him．He avoided making any commitments．)。commission n．授权，委托；佣金，回扣。offer n．提议；提供(物)。obligation n.责任，义务。