In concluding your direct reply letter，you should（）

A.sign off with a familiar expression such as "If I may be of further assistance，please don't hesitate to call me."

B.omit your name but include the company name in the signature block.

C.avoid repeating the information provided or referring to its use.

D.provide specifics if further action is requireD.

正确答案：provide specifics if further action is required.