Why did Pierre refuse to leave his job?

参考解析：

细节理解题。根据第二段中的“Every morning at five, Pierre arrived at the milk company’s stables to find Joseph waiting for him, Pierre would call, ‘Good morning, my old friend.’，as he climbed into his seat, while Joseph turned his head toward the driver.”，第七段“But Pierre refused to leave his job. He said his life would be nothing if he could not drive Joseph every day. “We are two old men,” he said to Jacques. “Let us wear out together. When Joseph is ready to leave, then I too will do so.””。可知，皮埃尔和约瑟夫互相了解，合作默契，他不愿意和约瑟夫分开，所以才拒绝辞职。另外三项没有涉及。故选C。