Read the passage given below and solve the questions based on it.
Mr Bose can do a job in two days if his four secretaries A, B, C and D are all present. His efficiency got reduced to respectively as A, B, C and D remain absent. In any day only one secretary remains absent. Also Mr Bose finishes his work exactly in integral number of days.
Which of the following secretaries cannot be absent for an odd number of days?