Re: ACME Midwest Sales Manager: I am unhappy to report that

(A) does not address the reasons why the ACME Midwest Sales Office had a bad quarter.
The response nowhere needs to address this matter in the given context.

(B) neglects the possibility that overall sales have increased dramatically.
The response is only talking about the performance/sales of the South sales office.The above point doesn't interfere with that.

(C) assumes an increase in sales percentage resulted from increased performance.
The response is neglecting the fact that maybe the net company sales had reduced owing to bad performances from other sales offices.
Say, initially, the net company sales was 100 and the south sales office share was 10. Now, if due to bad performances across, the net company sales decreased to say 20, and the south sales office share was 5, then actually this relative increase in percentage wouldn't have resulted in an increased performance.

(D) uses percentage data when he should be using absolute number data.
As both the percentages are related to the same office, the percentage data is correct, for a relative comparison.[Note, that extrapolating this increase in percentage to increased performance is not correct, as discussed above]

(E) neglects to consider other sales offices.
This is not required for the given response.He was only talking about the share and performance of the South sales office.