To fund a public works project, a representative from the Austrian government travels to New York to sell a diamond necklace from the Imperial Treasury. TopHat Jewels, a U$.$S$.$ company, enters into a contract with the Austrian government and pays the government representative for the necklace. However, when the owner of TopHat later travels to Vienna to collect the necklace, the Austrian government breaches the contract by refusing to sell. If TopHat sues the Austrian government for breach of contract in a U$.$S$.$ court, which of the following is the most likely outcome?

Multiple Choice

The Austrian government would be subject to U$.$S$.$ jurisdiction because it engaged in a commercial enterprise on U$.$S$.$ soil.

The Austrian government would be subject to U$.$S$.$ jurisdiction because it explicitly waived its immunity.

The Austrian government would be subject to U$.$S$.$ jurisdiction because their actions directly affect U$.$S$.$ interests.

The Austrian government would be exempt from U$.$S$.$ jurisdiction under the doctrine of sovereign immunity.