og-104

1. spending on reseach and development by united states businesses for 1984 showed an increase of about 8 percent over the 1983 level. this increase actually continued a downward trend evident since 1981-when outlays for reseach and development increased 164 percent over 1980 spending. clealy the 25percent tax credit enacted by congress in 1981,which was intended to promote spending on research and development, didi little or nothing to stimulate such spending.
the conclusion of the argument above cannot be true unless which of the following is true?

the answer is "in the absence of the 25percent tax credit, business spending for research and development after 1981 would not have been substantially lower than it was."

i understand 'without tax credit, business spending for research and development after 1981 would have been substantially lower than it was.'
可我决觉得答案和刚好和它解释的逻辑相反？