Concept:A group of companies is a business combination in which one parent company controls several other companies.
Explanation:A group is not just any random collection of firms or industries.
It is formed when a holding company acquires more than half of the shares or voting power of other companies.
The companies that are controlled in this way are called subsidiaries.
The holding company together with all of its subsidiaries is known as a group of companies.
Associates are different because the investing company only has significant influence over them, not full control.
Therefore, associates do not form a group structure with the holding company.
This shows that a group of companies properly consists of subsidiaries and their holding company.
Answer:A. subsidiaries and their holding company