Among types of carrier ownership, ______ are privately or public

Among types of carrier ownership, ______ are privately or publicly owned companies committed to performing a movement service of the same quality for all shippers on an equal basis and without discrimination.
A、common carriers
B、contract carriers
C、private carriers
D、united carriers
【正确答案】：A
【题目解析】：Common carriers are privately or publicly owned companies committed to performing a movement service of the same quality for all shippers on an equal basis and without discrimination.参见教材P190。