In the Context of Determining How Much to Spend on Advertising,which

In the context of determining how much to spend on advertising,which of the following statements is true about the per-unit expenditure approach?

A) This method is popular with higher-priced merchandise.
B) The basic philosophy underlying this approach is that advertising is defensive.
C) This approach is often used in conjunction with the research approach.
D) This approach views sales as a function of advertising,rather than advertising as a function of sales.