There are six teachers A, B, C, D, E and F in a school. Each teacher has to teach two subjects, one compulsory and the other optional. D's optional is History, while three others have it as compulsory subject. E and F have Physics as one of their subjects, F's compulsory subject is Mathematics, which is an optional subject of both C and E. History and English are A's subjects but in term of compulsory and optional subjects, they are reverse of D's. Chemistry is an optional subject of one of the teachers. There is only one female teacher, who has English as her compulsory subject.