Which of the following statements about preferred stock dividends is true?

Preferred stock dividends must be approved by the board of directors, which is why this statement is accurate. Preferred shareholders typically receive dividends before common shareholders, but the payment of these dividends is not guaranteed by law. Instead, the decision to distribute these dividends lies with the company's board, which has the authority to declare dividends based on the company's financial status and strategy.

Other options include assertions that dividends are guaranteed by law, which is false; while preferred stockholders have a higher claim to dividends than common stockholders, these payments are not legally mandated. Claiming that preferred stock dividends do not need board approval is also incorrect; board approval is required for dividends to be declared and paid. Lastly, while dividends may differ based on the company's performance, they are usually fixed and not variable, which contrasts with common stock dividends that can change.