An advertiser wants to know whether campaign strategy A had significantly different performance than campaign strategy B in terms of additional sales. The campaigns both ran at the same time against mutually exclusive portions of the advertiser's customer base.

What is the null hypothesis of the test design?

A. Sales Lift A = 0, Sales Lift B < 0

B. Sales Lift A = Sales Lift B

C. Sales Lift A >=Sales Lift B

D. Sales Lift A > 0, Sales Lift B = 0