Human Development Index (HDI) is defined as "a composite index combining indicators representing three dimensions, longevity (life expectancy at bih), knowledge (adult literacy rate and mean years of schooling) and income (real GDP per capita in purchasing power parity in US dollars)."\r\nRef: Preventive and Social Medicine, by K.Park, 19th edition, Page 15-17.

Per capita income is not included among the indicators of Physical Quality of Life as it does not measure the economic growth but instead it it measures the social. economic and political policies. While the other three options are the indicators which consolidate the Physical Quality of Life. Ref: Park's Textbook of Preventive and Social Medicine 19th edition; Page 16.