please help with this two question

7. What is the volume of oxygen required for the complete combustion of 50cm3 of methane at room temperature and pressure? A. 100cm3 B. 50cm3 C. 25cm3 D. 10cm3 8. When excess sulphur is burnt with 1mol of oxygen to form sulphur dioxide, which of the following statements are correct? (Assume that the volumes of gases are all measured at room temperature and pressure; molar volume of gas at room temperature and pressure =24.0dm3mol1 ) (1) The mole ratio of sulphur dioxide to oxygen is 1:1. (2) 24.0dm3 of sulphur dioxide form. (3) 24.0dm3 of oxygen are consumed. A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3)