Analysis of test questions: the forms of financial expenditure mainly include economic construction expenditure, science, education, culture and health expenditure, administrative management and national defense expenditure, social security expenditure, debt expenditure and so on. The funds invested in rural compulsory education are the financial expenditure on education, and C meets the meaning of the question; Administrative expenditure is the expenditure of financial investment in government funds, a does not meet the meaning of the question; Expenditure on cultural undertakings and scientific research is the expenditure of financial investment in cultural undertakings and scientific research, and BD does not meet the meaning of the question. The answer to this question is C.