ZIM Forum - Diễn đàn hỏi đáp Tiếng Anh

Actually, regardless of the country's policies,the trend does coincide with the use and subsequent prohibition of tetraethyl lead in petrol, which has been know for years as a cause of agressive behaviour. Therefore, countries that still use leaded petrol are being urged to stop using "it" to help improve health and crime prevention

The word "it" in paragraph refers to A. Leaded petrol B. Agressive behaviour C. Subsequent prohibition D. Crime prevention