Explanation:

- Human development involves improving the quality of human life, enhancing the well-being and opportunities of people. It takes into account education, health, income, and other factors that contribute to welfare.

- An Index: Human development is measured as an index called the Human Development Index (HDI). The HDI is a composite statistic that assesses human welfare through life expectancy, education level, and income per capita indicators.

- A Parameter: This refers to a measurable factor that helps define a system or set the conditions of its operation, not specifically summarizing overall development or welfare.

- An Attribute: This describes a characteristic or inherent part of something, and doesn’t capture the quantitative aspects needed to assess human development comprehensively.