Which one of the following countries of South-West Asia does not open out to the Mediterranean Sea?

The correct answer is Jordan.

To understand why Jordan does not open out to the Mediterranean Sea, we can analyze the geographical location and coastlines of the countries listed in the options:
1. Syria: Located in the northern part of Western Asia, Syria has a western coastline along the Mediterranean Sea, stretching for about 193 kilometers (120 miles) between Turkey to the north and Lebanon to the south.
2. Lebanon: Situated south of Syria, Lebanon has a long western coastline that lies entirely along the Mediterranean Sea.
3. Israel: Located south of Lebanon, Israel features a western coastline along the Mediterranean Sea, extending from its northern border with Lebanon to the Gaza Strip in the south.
4. Jordan: Situated east of Israel and the West Bank, Jordan is almost completely landlocked. Its only access to marine waters is in the extreme southwest at the Gulf of Aqaba, which opens into the Red Sea, rather than the Mediterranean Sea. Jordan is separated from the Mediterranean Sea by the territory of Israel and the West Bank.

Therefore, among the given South-West Asian countries, Jordan is the only one that does not open out to the Mediterranean Sea.