Which of these countries does not have a coastline on the Caspian Sea?

Uzbekistan does not have a coastal border on the Caspian sea.

The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. It covers 143,550 sq mi (372,000 km2) (excluding the highly saline lagoon of Garabogazköl to its east) and a volume of 78,200 km3 (19,000 cu mi). It has a salinity of approximately 1.2% (12 g/l), about a third that of average seawater.

It is bounded by Kazakhstan from mid-north to mid-east, Russia from mid-north to mid-west, Azerbaijan to the southwest, Iran to the south and adjacent corners, and Turkmenistan along southern parts of its eastern coast.

Uzbekistan, officially the Republic of Uzbekistan is a landlocked country in Central Asia. It is surrounded by five countries: Kazakhstan to the north; Kyrgyzstan to the northeast; Tajikistan to the southeast; Afghanistan to the south, Turkmenistan to the south-west. Its capital and largest city is Tashkent. Uzbekistan is part of the Turkic languages world, as well as a member of the Organisation of Turkic States. Uzbek language is the majority-spoken language in Uzbekistan. Islam is the predominant religion in Uzbekistan, most Uzbeks being Sunni Muslims.