C
Test question analysis: At present, 65% of China’s invention patents, more than 75% of enterprise technological innovations, and more than 80% of new product developments are It is done by small and medium enterprises. This shows that small and medium-sized enterprises have injected vitality into the development of our country's economy and play an important role in building an innovative country. Choose ① ④. It is the state-owned economy that controls the overall situation of economic operation. Do not choose ②. The main body of my country's national economic development is the public ownership economy, so do not select ③. The answer to this question is C.