Which of the following would be the most effective closing statement in a routine action request letter?
A、Please send a contract for heating and ventilation work by April 1 to allow installation to begin by April 15.
B、We hope you can get our work completed in a timely manner.
C、Thanking you in advance for sending a copy of the contract for installation of a new HVAC system by April 1.
D、I would appreciate receiving a copy of the contract for your proposed installation at your earliest possible convenience.