Question: The city where Thomas Carey died is the county seat of what county?

Context paragraphs:
Cerro Gordo County Courthouse (Iowa): The Cerro Gordo County Courthouse is located in Mason City, Iowa, United States.  When Cerro Gordo County was created in 1855 and Mason City was selected to be the county seat.  Dissatisfaction in the western part of the county led the Iowa legislature to appoint three new commissioners who would move the county seat to Livonia.  A courthouse was built there.  A petition signed by over half of the citizens of the county requested that the county seat be moved back to Mason City.  Mason City also won the election in 1858 to decide the matter 155-48.  Two courthouses have stood in Mason City prior to the present Modernist structure that was occupied by the county in 1960.  It had been built as the Standard Oil Building, and was acquired by the county in 1959 for $159,400 and then remodeled for their use.

Ellicott City, Maryland: Ellicott City is an unincorporated community and census-designated place, along with being the county seat of local government in Howard County, Maryland, United States.  It is part of the Baltimore Metropolitan Area.  The population was 65,834 at the 2010 census.  Founded in 1772, the town contains the B. & O. Railroad Museum's branch at the Ellicott City Station, built in 1830 as the first terminus of the initial line.  The downtown historic district is located in the valley of the small Tiber River, with its east end abutting the Patapsco River, which forms the Baltimore County line.  As of the 2000 census, Ellicott City surpassed Towson (county seat of neighboring Baltimore County) for the first time, as the largest unincorporated county seat in the country.

Norman, Oklahoma: Norman is a city in the U.S. state of Oklahoma 20 mi south of downtown Oklahoma City in its metropolitan area.  The population was 110,925 at the 2010 census.  Norman's estimated population of 120,284 in 2015 makes it the third-largest city in Oklahoma, and the city serves as the county seat of Cleveland County.

Thomas Carey (English politician): Thomas Carey (died 9 April 1634) was an English Member of Parliament.

Mason, Michigan: Mason is a city in the U.S. state of Michigan.  It is named after the state's first governor, Stevens T. Mason.  As of the 2010 census, the city population was 8,252.  It is the county seat of Ingham County.  Mason is the only city in the U.S. that serves as a county seat ahead of a state capital, with the capital of Lansing also in Ingham County.  Despite Mason being the county seat, many county offices and courtrooms are located in Lansing.

Van Buren, Missouri: Van Buren is a city that is the county seat of Carter County, Missouri, in the United States.  It is the largest town in Carter County.  Van Buren was founded in 1833 as the county seat of Ripley County and was named after then Vice President of the United States, Martin Van Buren.  In 1859 Van Buren became a part of the newly created Carter County and was subsequently selected to be the county seat.  The 2010 U.S. Census shows Van Buren with a population of 819, a decrease of 3.1 percent from its 2000 population of 845.

Johnston Library: The Johnston Library is a historic library located at 210 W. 10th St. in Baxter Springs, Kansas.  The building was constructed in 1872 to serve as a courthouse during Baxter Springs' unsuccessful attempt to become the Cherokee County seat.  Though Baxter Springs had lost an election to choose the county seat in 1869 to Columbus, supporters of both cities had attempted to fraudulently swing the election in their favor, and Baxter Springs hoped it could still become county seat in the future.  The building initially served as the county jail and sheriff's office until Columbus completed its jail in 1880.  After this, Baxter Springs ultimately gave up its attempts to become the county seat, and the building became its city hall.  In 1905, resident Niles P. Johnston bequeathed $5,000 to the city to start a library, and the city hall building was chosen to house it.

Boone County Sheriff's Department (Missouri): The Boone County Sheriff's Department is the agency responsible for general law enforcement, court services, and corrections services in Boone County, Missouri.  It is responsible for law enforcement in unincorporated Boone County, as well as in several municipalities.  Several cities including Columbia, as well as the University of Missouri, have their own police departments; however, all departments house prisoners in the Boone County Jail, operated by the BCSD.  The current sheriff of Boone County is Dwayne Carey, who has held the position since 2005, and ran unopposed in 2008 and 2012.  The BCSD is headquartered in Columbia, which is the county seat and the largest city in Boone County.

Bellville, Texas: Bellville is a city in the U.S. state of Texas and the seat of Austin County.  The city's population was 4,097 at the 2010 census.  Bellville was named for Thomas B. Bell, one of Stephen F. Austin's earliest colonists, after he and his brother donated land for the new county seat established by voters in 1846.  The original county seat was located in San Felipe.  Bellville is located at the intersection of State Highway 36 and State Highway 159 as well as FM 529, FM 1456, and FM 2429.  It is home to Trump Cafe, a restaurant named in honor of President Donald Trump.

Thomas Carey (baritone): Thomas Carey (29 December 1931 – 23 January 2002) was an American operatic baritone.  Born in Bennettsville, South Carolina, he served in the United States military during the Korean War.  After leaving the service he studied singing at the Henry Street Settlement and at City College of New York.  In 1970 he performed the role of Mel in the world premiere of Michael Tippett's "The Knot Garden" at the Royal Opera House in London.  From 1969 until his death of pancreatic cancer in Norman, Oklahoma he taught on the voice faculty of the University of Oklahoma.  He was married for many years to the contralto Carol Brice who had pre-deceased him in 1985.

Supporting paragraphs: Thomas Carey (baritone) Norman, Oklahoma
Answer: Cleveland County