Answer:
DIVISION OF LABOUR
Explanation:
Division of labour is : allocating different subparts of a task process to different people, to attain better efficiency. Better efficiency is attained by - labourers being specifically specialised in that subsection task, which increases their individual & hence organisation efficiency.
Elisa: opening her new business & assigning tasks to employees - is an example of the same.
All other options are inapt because: Management departmentalisation is dividing organisation into specialised niche departments. Mass production economies is cost reduction due to bulk quantity production. Specialisation of priorities is developing competitive advantage by research & innovation.