The longest continuous railway line in the world runs across which of the following pairs of cities?

Introduction / Context:
This question concerns world geography and transportation. The longest continuous railway line in the world is a famous fact related to the Trans Siberian Railway in Russia. It stretches across a vast distance, connecting the western part of the country with the far eastern region. The question asks which pair of cities represents this line among the given options.

Given Data / Assumptions:

• The focus is on the world's longest railway line.
• Several city pairs are listed from different countries.
• The learner must identify the pair that corresponds to the long Trans Siberian route.

Concept / Approach:
The Trans Siberian Railway is often described from Moscow to Vladivostok, covering about nine thousand kilometres across Russia. In some older general knowledge references, the western terminus is mentioned as Leningrad, the former name of Saint Petersburg, as part of an extended route connecting the Baltic region to Vladivostok in the far east. The key city consistently associated with the eastern end is Vladivostok. Among the options given, the only pair that includes Vladivostok and represents this vast Russian route is Leningrad and Vladivostok.

Step-by-Step Solution:

Verification / Alternative check:
To verify, remember that the Trans Siberian Railway is widely cited in atlases and general knowledge books as the longest continuous railway line in the world. It traverses the breadth of Russia and terminates at Vladivostok. Older references use the name Leningrad for Saint Petersburg, and the extended line connecting that region to Vladivostok is used in many exam questions. Therefore, matching Vladivostok with a major Russian city like Leningrad confirms the correct option.

Why Other Options Are Wrong:
New York and Seattle: These cities are in the USA and are connected mainly by multiple rail and road routes, but not by the longest railway line in the world.

Trivandrum and Guwahati: These Indian cities are far apart but do not host the world's longest continuous rail route.

Perth and Sydney: Australia has long railways, including the Indian Pacific route, but these are still shorter than the Trans Siberian Railway.

Common Pitfalls:
Some candidates may be tempted by the Australian option because the Indian Pacific route is also famous for its length. Others may be confused by the old name Leningrad and fail to associate it with Russia. To avoid such mistakes, remember that Vladivostok is the signature city linked with the world's longest railway, and any option containing Vladivostok is a strong candidate. Also recall that Leningrad is the old name of Saint Petersburg, linking it clearly to Russia.

Final Answer:
The longest continuous railway line in the world connects Leningrad and Vladivostok, representing the Trans Siberian route in Russia.