关于OG16第57题官方解释的疑惑

　　(A) Because an oversupply of computer chips has sent prices plunging,

　　(B) Because of plunging prices for computer chips, which is due to an oversupply,

　　(C) Because computer chip prices have been sent plunging, which resulted from an oversupply,

　　(D) Due to plunging computer chip prices from an oversupply,

　　(E) Due to an oversupply, with the result that computer chip prices have been sent plunging,

OG对C选项的解释说the violation of chronological order is confusing, 想请问各位NN，这里confusing在哪里，怎么破坏了时间顺序？have been sent和正确选项A都用的present-perfect.

还有是D选项的解释：This backward description of the events behind the announcement of factory closing is confusing and awkward.想请问这句话怎么理解？

Thx in advance