Given below are some of the methods of Demand Forecasting relating to Human Resource Planning. 
    (a)    Managerial Judgement        (b)    Work-Study Technique
    (c)    Expert Opinion                     (d)    Delphi Technique
    (e)    Group Brainstorming            (f)    Nominal Group Technique
    Choose the correct option from those given below, which come under the qualitative methods for demands forecasting: