Question: KRKI (99.5 FM, "True Country 99.5/107.9") is a radio station, it airs a Country format, the station is licensed to serve Keystone, in which state

Context paragraphs:
KXBL: KXBL is a classic country radio station known as "Big Country 99.5" ("Big Country" was a slogan 1170 KFAQ used during its country music heyday).  Located in Henryetta, Oklahoma, it broadcasts to the Tulsa, Oklahoma area on 99.5 FM.  The station is owned by E.W. Scripps Company.  Its studios are located in Midtown Tulsa and shares a transmitter with television station KTPX-TV in Mounds, Oklahoma.

KXZT: KXZT is an American radio station licensed by the Federal Communications Commission (FCC) to broadcast at 107.9 MHz from Newell, South Dakota, covering the Rapid City and Black Hills area.  On April,14 2017 it went on air as a simulcast tower for True Country 99.5/107.9.  The tower is owned and operated by Badlands Broadcasting.  KXZT serves the Northern Black Hills including Lead, Deadwood, Spearfish, Belle Fourche, and Sundance, WY.

CKTY-FM: CKTY-FM is a Canadian radio station broadcasting at 99.5 FM in Truro, Nova Scotia.  It plays a country music format branded as "Cat Country 99.5".  The station has been on the air since September 10, 1947.  It originally broadcast at 1400 AM as CKCL then to 600 in 1956, and received CRTC approval to move to 99.5 FM in 2001 after shutting down the AM 600 frequency.

KQBR: KQBR (99.5 FM, "Lonestar 99.5") is a radio station broadcasting a country music format.  Licensed to Lubbock, Texas, United States, and broadcasting on FM frequency 99.5 MHz, The station is currently under ownership of Townsquare Media.  Its studios and transmitter are located in south Lubbock.

WYMJ: WYMJ (99.5 FM, "Power Country 99.5") is a radio station licensed to serve New Martinsville, West Virginia.  The station is owned by the Dailey Corporation.  It airs a country music format.

WGMW: WGMW is a commercial radio station in LaCrosse, Florida, broadcasting to the Gainesville, Florida area on 99.5 FM.  The station was owned by JVC Media and previously had broadcast a Dance Top 40 format billed as "Party 99.5," whose direction was patterned after its sister station in Long Island, New York, WPTY.  Prior to the flip on June 1, 2013, it had programmed a news/talk format as 99.5 The Star.  On December 26, 2013, WBXY and its Dance format moved over to WXJZ, where they simulcasted until January 2014, when JVC announced the sale of the station to RDA Broadcast Holdings, LLC, who on June 4, 2014, flipped WBXY to a simulcast of WGMA, a new station that signed on at 99.7 and serving the Ocala area.

KRKI: KRKI (99.5 FM, "True Country 99.5/107.9") is a radio station licensed to serve Keystone, South Dakota.  The station serves Rapid City, South Dakota, with an on-channel broadcast booster licensed as KRKI-FM1.  The station is owned by Oregon Trail Broadcasting, LLC, through licensee Bad Lands Broadcasting Company, Inc.  KRKI airs a Country format.

WCRB: WCRB (99.5 FM) is a non-commercial radio station licensed to Lowell, Massachusetts and based in the Brighton area of Boston, which serves the Greater Boston area.  It broadcasts a classical music format; it existed as a commercial station from the early 1950s until December 2009, and as a listener-supported station since then, having then been acquired by the WGBH Educational Foundation.  Programming is also simulcast on the second HD Radio channel of WGBH (89.7 FM), allowing WCRB to reach some portions of the Boston area that cannot receive 99.5, as well as WJMF (88.7 FM) in Smithfield, Rhode Island (serving nearby Providence), the second HD Radio channel of WCAI (90.1 FM) in Woods Hole, W242AA (96.3 FM) in Kendall Square, Cambridge (designed to serve Beacon Hill, Boston), and W295BL (106.9 FM) in Manchester, New Hampshire.

Country: A country is a region that is identified as a distinct national entity in political geography.  A country may be an independent sovereign state or one that is occupied by another state, as a non-sovereign or formerly sovereign political division, or a geographic region associated with sets of previously independent or differently associated people with distinct political characteristics.  Regardless of the physical geography, in the modern internationally accepted legal definition as defined by the League of Nations in 1937 and reaffirmed by the United Nations in 1945, a resident of a country is subject to the independent exercise of legal jurisdiction.

KPLX: KPLX (99.5 FM, "99.5 The Wolf") is an American commercial radio station broadcasting a country music format on 99.5 FM, serving the Dallas/Fort Worth metroplex in Texas and is under ownership of Cumulus Media.  The station's studios are located in the Victory Park district in Dallas just north of downtown, and its transmitter is located in Cedar Hill, Texas.

Supporting paragraphs: KRKI Country
Answer: South Dakota