The correct answer is option 'D' - Bolivian organisation, FEDECOR.

Explanation:

Sectional interest groups are organizations that represent the interests of a specific section or group of society. They advocate for the concerns and demands of their members, who share common characteristics or occupations. These interest groups work towards promoting and protecting the interests of their members.

- Trade unions: Trade unions are organizations formed by workers to protect their rights and advance their interests in relation to their employment. They represent the collective interests of workers in specific industries or sectors.
- Business associations: Business associations are organizations that represent the collective interests of businesses and industries. They advocate for policies and regulations that benefit their members and the business community as a whole.
- Professional groups: Professional groups are associations formed by individuals working in the same profession or field. These groups represent the interests and concerns of professionals and work towards enhancing the status and well-being of their members.

On the other hand, the Bolivian organization FEDECOR does not fit the definition of a sectional interest group. FEDECOR stands for Federación de Corregidores de Bolivia, which translates to Federation of Corregidors of Bolivia. Corregidors are local government officials in Bolivia who are responsible for maintaining law and order in their areas. FEDECOR is a federation that represents the interests and concerns of these local government officials.

Unlike sectional interest groups, FEDECOR does not represent a specific section or group of society. Instead, it represents a specific occupation within the government. Therefore, FEDECOR is not considered a sectional interest group.

In conclusion, while trade unions, business associations, and professional groups are examples of sectional interest groups, the Bolivian organization FEDECOR does not fall under this category.