Answer:

Introduction:
The Arabian Sea is a region of the Indian Ocean bounded by the Arabian Peninsula and the Indian subcontinent. It is an important body of water that is bordered by several countries. However, one of the countries on the list does not have a coastline with the Arabian Sea.

Explanation:
The country that does not have a coastline with the Arabian Sea is Afghanistan.

Reasoning:
Let's consider each option and analyze whether the country has a coastline with the Arabian Sea or not:

- Afghanistan: Afghanistan is a landlocked country in Central Asia and does not have a coastline with any sea or ocean. It is surrounded by several countries such as Pakistan, Iran, Turkmenistan, Uzbekistan, Tajikistan, and China.

- Pakistan: Pakistan is located in South Asia and shares a border with the Arabian Sea. The coastline of Pakistan stretches for about 1,046 kilometers along the Arabian Sea, from the Iranian border in the west to the Indian border in the east.

- Oman: Oman is situated in the southeastern coast of the Arabian Peninsula and it has a coastline with the Arabian Sea. The country is known for its beautiful beaches and ports along the Arabian Sea.

- Iran: Iran is located in Western Asia and has a coastline along the Persian Gulf, which is an extension of the Arabian Sea. The Persian Gulf is considered a part of the Arabian Sea and Iran has access to this body of water.

Therefore, the correct answer is Afghanistan as it is a landlocked country and does not have a coastline with the Arabian Sea.

Conclusion:
Among the given options, Afghanistan does not have a coastline with the Arabian Sea. It is a landlocked country and is surrounded by other countries. Pakistan, Oman, and Iran have coastlines with the Arabian Sea.