Which of the following countries is landlocked?

Austria is classified as a landlocked country because it is surrounded entirely by land and does not have any coastlines or direct access to oceans or seas. This geographical characteristic is significant as it impacts trade, transport, and other economic practices, often necessitating reliance on neighboring countries for access to maritime routes.

In contrast, the other options—Italy, Greece, and Portugal—are all coastal nations, featuring extensive coastlines that provide them access to the Mediterranean Sea and the Atlantic Ocean. This access enables these countries to engage in maritime trade, tourism, and fishing activities, which are critical components of their economies.