The most accurate response is: The Vedas provide a record of how the Indo-Aryans lived.
The Vedas, which are ancient texts composed in Sanskrit, contain hymns, rituals, and discussions that reflect the lifestyle, culture, and societal organization of the Indo-Aryans, including their reliance on cattle and milk before transitioning to agriculture. Archaeological evidence and the study of tools complement this understanding but the Vedas are a primary source for insights into their way of life.