Answer:
The correct answer is A
Step-by-step explanation:
Sent means that the message or the communication is the cause which is to be transmitted or conveyed to the destination.
So, in this case, Mining corporation offers to sell the Refining company, a set of services in order to aid the process of refining. And the East China (Refining Company), sends the acceptance to the corporation, therefore, the communication mode will be effective or applied when it is sent to the corporation.