The correct answer is option 2: Leningrad and Vladivostok. Leningrad, now known as Saint Petersburg, is located in Russia`s western part, while Vladivostok is located in the country`s far eastern part. The railway line that connects these two cities is known as the Trans-Siberian Railway, and it is considered the longest railway line in the world. Spanning a distance of approximately 9,289 kilometers (5,772 miles), the Trans-Siberian Railway passes through various landscapes, including forests, mountains, and plains. It was built between 1891 and 1916 and is an important transportation route in Russia, allowing for the transportation of goods and people between different parts of the country.