The correct answer is option 2, M. A. K. Pataudi. M. A. K. Pataudi, also known as Tiger Pataudi, was the captain of the Indian cricket team during the 1960s. Under his leadership, India achieved their first-ever overseas test victory against New Zealand in 1968.

Option 1, C. K. Nayudu, is incorrect. Though Nayudu was an important figure in Indian cricket as one of the first Indian cricket captains and a prominent player in the pre-independence era, he did not lead India to their first overseas test victory.

Option 3, Sunil Gavaskar, is also incorrect. Gavaskar, a legendary Indian cricketer, played a significant role in India`s success in test cricket during his career. However, he did not lead India to their first overseas test victory.

Option 4, Bishen Singh Bedi, is incorrect as well. Bedi was a renowned left-arm spinner and a former Indian cricket captain, but he did not captain the team to their first overseas test victory.

In conclusion, M. A. K. Pataudi led India to their first overseas test victory, making option 2 the correct answer.