Correct Answer: Both assertion and reason are correct, and the reason explains the assertion.

Solution : The correct answer is (a) Both assertion and reason are correct, and the reason explains the assertion.

The assertion is correct because the nature of management indeed varies based on the size and complexity of the organization. Smaller organizations may have simpler management structures and processes, while larger and more complex organizations require more elaborate and sophisticated management systems to handle their intricacies.

The reason is correct because it provides an explanation for why the nature of management varies. Larger organizations with more extensive operations, a greater number of employees, and diverse functions require more complex management structures and processes to effectively manage their resources and operations. Therefore, the reason aligns with and explains the assertion.