关于comma having been... 修饰的问题

idsamsang

5.
Rather than accept the conventional wisdom that the earth was flat, Christopher Columbus was sent by the king and queen of Spain to see if he could reach India by traveling west.  
• Rather than accept the conventional wisdom that the earth was flat, Christopher Columbus was sent by the king and queen of Spain to see if he could reach India by traveling west.  
• Rather than accepting the conventional wisdom that the earth was flat, Christopher Columbus was sent by the king and queen of Spain to see if he could reach India by sailing west.
• Instead of accepting the conventional wisdom that the earth was flat, Christopher Columbus sailed west to see whether he could reach India, having been sent by the king and queen of Spain.
• Rather than accept the conventional wisdom that the earth was flat, Christopher Columbus sailed west to see whether he could reach India, having been sent by the king and queen of Spain.
• Instead of accepting the conventional wisdom that the earth was flat, Christopher Columbus was sent by the king and queen of Spain to sail west to see if he could reach India.

这道题选择的时候被 D 选项 having been sent by... 严重干扰，我的疑问是 having been sent 的动作是先于 动作sailed 吗？ 还是一个伴随状态修饰整个句子？

Inertiae

这道题有好几个decision point。明显的是1）被动的全是错了。如果是被动的话，拒绝接受常规思想的主语成为了西班牙的国王和王后了，但其实应该是哥伦比亚。这是明显的错误；2）gmat里是否应该用whether表示，所以用if的都可以排除。我们最后剩下c和d，即instead of和rather than的区别。平时来说两个都ok，但比较是动词时，stylistically rather than is preferred