Answer: A. specialization.
Explanation:
Specialization is staff training. Specialization is often additional criteria that need to be met to perform a particular job productively. Specialization can be mandatory or self-initiated. For example, a mandatory specialization may involve the involvement of new technologies in a particular business collective to concern all employees so that everyone must undergo certain training. Self-initiative specialization can imply the pursuit of career advancement. To achieve this, it is necessary to overcome some new business challenges, which can only be solved by specialization.