Read the following information carefully and answer the questions based on them. 

The staff of a bank are Mr A, Mr B, Mrs C, Miss D, Mr E and Miss F. The positions they occupy are manager, assistant manager, cashier, stenographer, teller and clerk, though not necessarily in that order. The assistant manager is the managers grandson, the cashier is the stenographers son-in-law. Mr A is a bachelor. Miss D is the tellers step sister and Mr E is the managers neighbour.  Mr B cannot have a grandson or son-in-law as he is only  20 years old.