The correct answer is option 4, Nile. The Nile is widely recognized as the longest river in the world. It stretches over 6,650 kilometers (4,130 miles) and flows through 11 countries in northeastern Africa, including Egypt, Sudan, and Ethiopia. The river has historically played a crucial role in the region`s civilization, with ancient Egyptian societies relying on the Nile`s annual flooding for agriculture and sustenance. Its source is debated, with the most commonly accepted origin being Lake Victoria in present-day Uganda. The Nile`s flow eventually culminates in the Nile Delta, where it empties into the Mediterranean Sea. With its remarkable length and significant influence on the region, the Nile holds great historical, cultural, and ecological significance.