Explanation:

Landlocked countries are cut off from sea resources such as fishing, and more importantly, have no access to seaborne trade, which makes up a large percentage of international trade. Thus, coastal regions tend to be wealthier and more heavily populated than inland areas. In the case of Laos, this disadvantage is strikingly apparent, as Laos is the only landlocked country in the whole of Southeast Asia. Hence option 1st is correct.