— I must apologize for _____ ahead of time.
— That’s all right.

1. A.
   letting you not know
2. B.
   not letting you know
3. C.
   letting you know not
4. D.
   letting not you know

–I must apologize for _____ ahead of time.  –That's all right.

A. letting you not know                   B. not letting you know

C. letting you know not                    D. letting not you know

. ---I must apologize for  ___________     ahead of time.    ---That’s all right.

A. letting you not know                B. not letting you know

C. letting you know not                D. letting not you know