To measure gender differences in terms of wealth, health, and education, the appropriate choice would be the Gender Development Index (GDI). The GDI specifically takes into account gender disparities in health (life expectancy), education (enrollment ratios, literacy rates), and economic participation, making it the most relevant option for assessing gender differences in these areas.
The other options, such as CPI, GINI coefficient, and GDP, do not specifically measure gender differences.