Final answer:
The debt to assets ratio is not a measure of profitability but rather a leverage and financial stability indicator, distinguishing it from profitability ratios like profit margin, gross profit margin, and earnings per share.
Step-by-step explanation:
The ratio that is not a measure of profitability among the options provided is d. debt to assets. Profitability ratios typically measure a company's ability to generate earnings relative to its revenue, assets, or shareholders' equity. Ratios such as profit margin, gross profit margin, and earnings per share are all common indicators of profitability. In contrast, the debt to assets ratio is a measure of leverage and financial stability, indicating the proportion of a company's assets that are financed with debt.