A machine shop has two machines, M1 and M2. Four jobs, A, B, C, and D need to be processed through machines M1 first and M2 second. Job A will take one hour on machine M1 and three hours on machine M2. Job B will take three hours on M1 and two hours on M2. Job C takes seven hours on M1 and three hours on M2. Job D requires five hours on M1 and one hour on M2. Using Johnson's rule, in what order should these jobs be done? Select one of the following answers:
ABCD
ACBD
DABC
DACB