What international document is issued by the Department of State?

The passport is the correct answer because it serves as an official document issued by the Department of State that certifies a person's identity and nationality for international travel. A passport is essential for U.S. citizens traveling abroad, as it allows them to enter foreign countries and return to the United States. The Department of State is responsible for processing passport applications, ensuring that the passports meet international standards, and managing various aspects of international travel documentation.

In contrast, while visas are critical documents for entry into other countries, they are typically issued by the country you wish to enter and not by the Department of State. An ID card can refer to various forms of identification, but it is not specifically an international document, and the Green Card is related to immigration status in the United States rather than serving a purpose for international travel. Thus, the passport is uniquely tied to the responsibilities of the Department of State regarding international travel documentation.