Final answer:
Managers should choose to issue equity to maximize the long-term share price of the firm.
Step-by-step explanation:
To maximize the long-term share price of the firm once its true value is known, managers should choose to issue equity rather than borrowing the $500 million. When a firm issues equity, it sells ownership of the company to the public and becomes responsible to a board of directors and shareholders. By issuing equity, the firm can raise the necessary capital without committing to scheduled interest payments and maintain control of its operations.