Each of the built-in costs of a product must bring in some profit at each stage: truckers must profit from transporting products, or they______ in business.
A．would not be
B．will not be
C．were not
D．can not be

A.
A．would
B.will
C.were
D.can

【参考答案】

A
or在此处的意思相当于orelse或otherwise，所以后面句子的谓语应用动词的虚拟形式。