a. The less pollution is caused by petrol and CNG operatedautomobiles. b. Alkanes which are having tertiary hydrogen (3°) can be oxidized to alcohols by KMnO4 c. Methane cannot be prepared by Kolbe's electrolytic method as methane is having only one carbon atom. This method is used to produce ethane and higher members. d. When alkyl chloride undergoes reduction with zinc and HCl, it produces alkane. Therefore, statements (a), (b) and (d) are correct.