Retained earnings accumulate from which of the following?

Retained earnings represent the portion of a company's net income that is retained in the business rather than distributed as dividends to shareholders. The accumulation of retained earnings occurs through the reinvestment of earnings over time since the firm's inception, which means that every year, after paying out dividends, the remaining profits are added to retained earnings. This is a critical aspect of how companies fund growth, acquisitions, and other investments without needing external financing.

As such, the correct choice focuses on the history of earnings that the company has generated and retained over the years. It encapsulates all profits retained after dividends, contributing to the firm's equity base and allowing the company to strengthen its financial position.

In contrast, the other options do not accurately reflect the source of retained earnings. The par value of issued shares refers to the nominal value assigned to shares and does not consider earnings or profits. Cash flows from financing activities pertain to the inflows and outflows of cash from equity and debt transactions, rather than retained earnings derived from operations. Similarly, income generated solely from investments can refer to separate investment income rather than profits from overall company operations and are not representative of the retained earnings that encompass operating profit retention.