[单选题]The paragraph is followed by an incomplete phrase or sentence which summarizes the main idea of the paragraph. Choose the missing words of the phrase or sentence.
A recent study has found that people who use an iPhone are cleverer than those who prefer Android devices. This is based on research that found states with more college graduates also tend to have higher iPhone sales. The study discovered that Alaska, Montana and Vermont have the largest number of iPhone users in the US. These states also have the highest percentage of college graduates.
