题目选项分析

Pharmaceutical companies spend more than ever on research and development; yet the number of new drugs patented each year has dropped since 1963. At the same time, profits- at constant 1963 dollars-for the industry as a whole have been steadily increasing.

Which of the following, if true, is the single factor most likely to explain, at least in part, the three trends mentioned above for money spent, drugs patented, and profits made?

【选项】The advertising budgets of the major pharmaceutical companies have grown at a higher rate than their profits have.