Final answer:
The matrix organizational form is typically favored by firms engaging in numerous similar projects due to its flexibility and efficient allocation of resources.
Step-by-step explanation:
When a firm engages in a large number of similar projects, the organizational form most likely to be preferred is the matrix organizational form. This structure allocates staff from different functional departments to projects as needed while maintaining their roles in their respective departments. It provides a flexible approach for firms handling multiple projects simultaneously, which is particularly beneficial when the projects are similar, as it allows for the sharing of resources and expertise effectively across projects.