All of the following are channels to get market information except______.A．to have commerc

All of the following are channels to get market information except______.

A．to have commercial counselor" s offices of our embassies stationed abroad

B．to promote the quality of our own products

C．to send trade groups abroad every now and then

D．to have face-to-face talks with foreign businessmen

请帮忙给出正确答案和分析，谢谢！