Information:  - Tajikistan (, or ), officially the Republic of Tajikistan ("Çumhuriji Toçikiston"), is a mountainous, landlocked country in Central Asia with an estimated 8 million people in 2013, and an area of . It is bordered by Afghanistan to the south, Uzbekistan to the west, Kyrgyzstan to the north, and China to the east. Pakistan lies to the south, separated by the narrow Wakhan Corridor. Traditional homelands of Tajik people included present-day Tajikistan, Afghanistan and Uzbekistan.  - The Yazgulyam River ( also spelled Yazgulem River ) is a tributary of the Panj ( upper Oxus ) in Vanj district , western Gorno - Badakhshan , Tajikistan . It flows in a narrow valley or gorge of some 100 kilometres northeast to southwest , roughly 38 ° 29  N 72 ° 06  E to 38 ° 13  N 71 ° 23  E. It lies between two high mountain ranges , the Vanj Range to the north and the Yazgulem Range to the south . Its headwaters are near the Fedchenko Glacier . Settlements in the valley include Matraun , Bdyn , Anderbak and Dzhamak . The Yazgulyami inhabitants number about 4,000 ( as of 1990 , estimate for 1940 is about 2,000 ) . In 1996 during the Tajik civil war , there was some fighting in Yazgulyam Gorge between Islamic Movement of Uzbekistan mujahidin and Tajik troops .  - The Panj River, also known as "Pyandzh River" or "Pyanj River" (derived from its Russian name "/Pjandž"), is a tributary of the Amu Darya. The river is 1,125 km long and forms a considerable part of the Afghanistan - Tajikistan border.  - Central Asia or Middle Asia is the core region of the Asian continent and stretches from the Caspian Sea in the west to China in the east and from Afghanistan in the south to Russia in the north. It is also colloquially referred to as "the 'stans" (as the six countries generally considered to be within the region all have names ending with the Persian suffix "-stan", meaning "land of") and is within the scope of the wider Eurasian continent.  - Pakistan (or ), officially the Islamic Republic of Pakistan, is a federal parliamentary republic in South Asia on crossroads of Central Asia and Western Asia. It is the sixth-most populous country with a population exceeding 200 million people. It is the 36th largest country in the world in terms of area with an area covering . Pakistan has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by India to the east, Afghanistan to the west, Iran to the southwest and China in the far northeast respectively. It is separated from Tajikistan by Afghanistan's narrow Wakhan Corridor in the north, and also shares a maritime border with Oman.  - Panj is a city in southern Tajikistan which is situated on the Afghan border, some south of the capital Dushanbe. It is located along the banks of the Panj River, from which it derives its name.    After reading the paragraphs above, we are interested in knowing the entity with which 'yazgulyam river' exhibits the relationship of 'mouth of the watercourse'. Find the answer from the choices below.  Choices: - arabian sea  - panj river  - sea
A:
panj river