Which of the Following Is Not a 'Task Variable

Which of the following is not a 'Task Variable'? 

A)  Tasks assigned by the organization to the persons involved in the purchase decision-making process. 
B)  Responsibilities assigned by the organization to the persons involved in the purchase decision-making process. 
C)  Competences assigned by the organization to the persons involved in the purchase decision-making process. 
D)  Remuneration of the persons involved in the purchase decision-making process.