Answer:
E) Stereotyping
Step-by-step explanation:
An stereotype is a concept, idea or way of being attributed to people in a preconceived way and without theoretical foundations, in this order of ideas the manager's beliefs are based on the idea that the old people don't have the capacity to learn new things or create new ways to do things because they are not prone to change for the experience that they have and the wrong thinking that the knowledge they got will be valid for all the life.