Grouping the jobs of similar nature and organizing them as a separate department typically creates a "Functional Structure."

So, the correct answer is:

1. A functional Structure.A functional structure is a common organizational design where jobs with similar functions or tasks are grouped together into separate departments or units. A functional structure is a common organizational design where jobs with similar functions or tasks are grouped together into separate departments or units. . 

2. A Divisional Structure: In a divisional structure, an organization is divided into separate divisions or units based on different criteria, such as products, geographical regions, customer groups, or markets served. 

3. An Informal Structure: An informal structure refers to the unspoken or unwritten relationships, networks, and communication patterns within an organization that are not part of the formal organizational chart.

4. A Managerial Structure: "Managerial Structure" is not a standard term in organizational design. It doesn't represent a well-defined organizational structure. The structure of an organization is typically classified into functional, divisional, matrix, network, or other common types.