The correct answer is option 4: "All of the above." This means that all three options mentioned in the question support the idea that the Rig-Vedic aiyans were a pastoral people.

Option 1 states that there are many references to the cow in the Rig Veda. In the Rig Veda, cows are revered and considered sacred. They are mentioned extensively in hymns, rituals, and prayers, which indicate their importance in the lives of the Rig-Vedic aiyans.

Option 2 suggests that most of the wars fought by the Rig-Vedic aiyans were for the sake of cows. This supports the notion that cattle played a significant role in their economy and societal structure.

Option 3 explains that gifts made to priests were usually cows and not land. This implies that cows held significant value and were considered valuable possessions that could be offered as a form of tribute or payment.

Therefore, all three options provide evidence that the Rig-Vedic aiyans were indeed a pastoral people who prioritized and depended on cattle in various aspects of their lives.