Which activity ratio is NOT included in the asset turnover measures?

The correct answer is highlighted by the fact that return on equity (ROE) is primarily a profitability ratio rather than an activity ratio. Activity ratios, such as asset turnover, months supply of land, and months supply of spec homes, focus on how effectively a company uses its assets to generate sales or manage its inventory.

Asset turnover specifically measures a company's ability to generate revenue from its assets, indicating the efficiency with which assets are utilized to produce sales. Similarly, both the months supply of land and months supply of spec homes pertain to inventory management, assessing how long current inventory levels will last given the current sales pace.

In contrast, return on equity assesses a company's profitability relative to shareholders' equity, focusing on the returns generated from shareholders' investments. As such, it does not provide insights about asset utilization or operational efficiency, which distinguishes it from the other options provided that relate more directly to how effectively a company is operating with its assets.