Answer:
A. to establish her credibility to speak for the company.
Explanation:
After this long period of the company's attempts to solve the problem, but to no avail, surely the problem had already escaleted. However, Maria, being the Vice President of Customer Affairs, shows clearly that the company is concerned enough to find a solution that can be satisfactory for the client. This sends a message to the customer that he or she is dealing with a reliable person in the company,