Question: The Benjamin River is a tidal river in Hancock County, a county located in the U.S. state of Maine, and its county seat is what?

Context paragraphs:
Jordan River (Maine): The Jordan River is a 5 mi tidal river in Hancock County, Maine, flowing to Mount Desert Narrows, the waterway that separates Mount Desert Island from the mainland.  The Jordan River forms the boundary between the towns of Lamoine and Trenton.

Hancock County, Kentucky: Hancock County is a county located in the U.S. state of Kentucky.  As of the 2010 census, the population was 8,565.  Its county seat is Hawesville.  Hancock is a prohibition or dry county.

Benjamin River: The Benjamin River is a tidal river in Hancock County, Maine.

Skillings River: The Skillings River is a 7 mi tidal river in Hancock County, Maine, flowing to Frenchman Bay.  For most of its length it forms the boundary between the towns of Hancock and Lamoine.

Hancock County, Ohio: Hancock County is a county located in the U.S. state of Ohio.  As of the 2010 census, the population was 74,782.  Its county seat is Findlay.  The county was created in 1820 and later organized in 1828.  It was named for John Hancock, the first signer of the Declaration of Independence.

Hancock County, Maine: Hancock County is a county located in the U.S. state of Maine.  As of the 2010 census, the population was 54,418.  Its county seat is Ellsworth.  The county was incorporated on June 25, 1789 and named for John Hancock, the first governor of the Commonwealth of Massachusetts.  The Commissioners are Antonio Blasi, Steven Joy, Percy Brown.

Bagaduce River: The Bagaduce River is a tidal river in the Hancock County, Maine that empties into Penobscot Bay near the town of Castine.  From the confluence of Black Brook and the outflow of Walker Pond ( ), the river runs about 14 mi north, northwest, and southwest, forming the border between Brooksville on its left bank and Sedgwick, Penobscot, and Castine on its right.

Hancock County, West Virginia: Hancock County is a county in the U.S. state of West Virginia.  As of the 2010 census, the population was 30,676.  Its county seat is New Cumberland.  The county was created from Brooke County in 1848 and named for John Hancock, first signer of the Declaration of Independence.  Hancock County is the northernmost point in both West Virginia and the Southern United States, being at the tip of the state's Northern Panhandle.

Little River (Damariscotta River): The Little River is a 2.1 mi stream and tidal river on Linekin Neck in the town of Boothbay in the U.S. state of Maine.  It is a small tidal river for its lower 1.4 mi , entering the Atlantic Ocean just west of the mouth of the Damariscotta River.

Penobscot County, Maine: Penobscot County is a county located in the U.S. state of Maine.  As of the 2010 census, the population was 153,923.  Its county seat is Bangor.  The county was established on 15 February 1816 from a portion of Hancock County when the area was still part of Massachusetts.  Penobscot County is home to the University of Maine.

Supporting paragraphs: Benjamin River Hancock County, Maine
Answer: Ellsworth