Final answer:
Portugal has a trade surplus of $50,000, as their exports ($400,000) are greater than their imports ($350,000), which indicates a positive balance of trade.
Step-by-step explanation:
If Portugal's imports are $350,000 and their exports are $400,000, they have a trade surplus of $50,000. This is calculated by subtracting imports from exports ($400,000 - $350,000 = $50,000). Therefore, the correct answer is D. A trade surplus of $50,000.
A trade surplus occurs when a country's exports exceed its imports, which is considered favorable for a country's economic health. In contrast, a trade deficit happens when imports exceed exports, which can be a concern for a country's economy, as it might indicate that the country is spending more on foreign products than it is earning from sales of its own goods.
It's important to note that the current account balance includes the trade balance, but it also includes other forms of international financial flows, such as earnings from investments abroad and transfer payments.