Which organizational structure is most suitable when the size of the organization is large, has diversified activities and operations require a high degree of specialization?

Functional structure

The correct answer is option 3- Functional structure.

Functional structure is most suitable when the size of the organization is large, has diversified activities and operations require a high degree of specialization

Functional structure- Grouping of jobs of similar nature under functional and organising these major functions as separate departments creates a functional structure. All departments report to a coordinating head. For example, in a manufacturing concern division of work into key functions will include production, purchase, marketing, accounts and personnel. These departments may be further divided into sections. Thus, a functional structure is an organisational design that groups similar or related jobs together. 

Suitability: It is most suitable when the size of the organisation is large, has a diversified activities and operations require a high degree of specialisation.