Explanation

Stock dividends do not affect a company's leverage ratios because:

• Stock dividends involve issuing additional shares to existing shareholders without any cash outflow
• They represent a transfer from retained earnings to paid-in capital within shareholders' equity
• Since there is no change in total assets or liabilities, leverage ratios (such as debt-to-equity, debt-to-assets) remain unchanged

In contrast:

• Extra dividends and regular cash dividends involve cash payments to shareholders
• These reduce retained earnings and total equity, which can increase leverage ratios
• The reduction in equity makes the company appear more leveraged

Therefore, stock dividends are the only option that does not impact leverage ratios.