Question: Which one of Astronaut Group 1 was NASA's first Chief of the Astronaut office?

Context paragraphs:
The Cape (1996 TV series): The Cape is an American dramatic TV series, with elements of science fiction, action/adventure, and drama, that was produced for syndication during the 1996–97 television season.  "The Cape" told the story of select members of the NASA Astronaut Corps at the Kennedy Space Center in Florida with a focus on their personal lives as they train for, and execute, Space Shuttle missions.  The series stars Corbin Bernsen as USAF Colonel Henry J. "Bull" Eckert, an experienced astronaut who, early in the series, was the Director of Astronaut Training but later in the series was also tasked with the responsibility of Chief of the Astronaut Office.

Alan Bean: Alan LaVern Bean (born March 15, 1932), (CAPT, USN, Ret.) , is an American former naval officer and Naval Aviator, aeronautical engineer, test pilot, and NASA astronaut; he was the fourth person to walk on the Moon.  He was selected to become an astronaut by NASA in 1963 as part of Astronaut Group 3.  He made his first flight into space aboard Apollo 12, the second manned mission to land on the Moon, at the age of thirty-seven years in November 1969.  He made his second and final flight into space on the Skylab 3 mission in 1973, the second manned mission to the Skylab space station.  After retiring from the United States Navy in 1975 and NASA in 1981, he pursued his interest in painting, depicting various space-related scenes and documenting his own experiences in space as well as that of his fellow Apollo program astronauts.

Robert L. Behnken: Robert Louis "Bob" Behnken (born July 28, 1970 in Creve Coeur, Missouri) is a United States Air Force officer, NASA astronaut and former Chief of the Astronaut Office.  Behnken holds a Ph.D in Mechanical Engineering and holds the rank of Colonel in the U.S. Air Force.  Col. Behnken has logged over 1,000 flight hours in 25 different aircraft.  He flew aboard Space Shuttle missions STS-123 and STS-130 as a Mission Specialist, accumulating over 378 hours in space, including 19 hours of spacewalk time.  Behnken was also assigned as Mission Specialist 1 to the STS-400 rescue mission.  He is married to fellow astronaut K. Megan McArthur.

Janet L. Kavandi: Janet Lynn Kavandi, a native of Carthage, Missouri, (born July 17, 1959) is an American scientist and a NASA astronaut.  She is a veteran of three Space Shuttle missions and has served as NASA's Deputy Chief of the Astronaut Office.

NASA Astronaut Group 5: NASA's Astronaut Group 5 was selected by NASA in April 1966.  Of the six Lunar Module Pilots that walked on the Moon, three came from Group 5.  The group as a whole is roughly split between the half who flew to the Moon (nine in all) and the other half who flew Skylab and Shuttle, providing the core of Shuttle Commanders early in that program.  This group is also distinctive in being the only time when NASA hired a person into the astronaut corps who had already earned astronaut wings, X-15 pilot Joe Engle.  John Young labelled the group the "Original Nineteen" in parody of the original seven Mercury astronauts.

Clifton Williams: Clifton Curtis "C.C." Williams Jr. (September 26, 1932 – October 5, 1967), (Major, USMC), was an American naval aviator, test pilot, mechanical engineer, Major in the United States Marine Corps, and NASA astronaut, who was killed in a plane crash; he had never been to space.  The crash was caused by a mechanical failure in a NASA T-38 jet trainer, which he was piloting to visit his parents in Mobile, Alabama.  The failure caused the flight controls to stop responding, and although he activated the ejection seat, it did not save him.  He was the fourth astronaut from NASA's Astronaut Group 3 to have died, the first two (Bassett and Freeman) having been killed in separate T-38 flights and (Chaffee) in the Apollo 1 fire earlier that year.  The aircraft crashed in Florida near Tallahassee within an hour of departing Patrick AFB.

Deke Slayton: Donald Kent "Deke" Slayton (March 1, 1924 – June 13, 1993), (Major, USAF) was an American World War II pilot, aeronautical engineer, test pilot who was selected as one of the original NASA Mercury Seven astronauts, and became NASA's first Chief of the Astronaut Office.

Mercury Seven: The Mercury Seven were the group of seven Mercury astronauts announced by NASA on April 9, 1959.  They are also referred to as the Original Seven or Astronaut Group 1.  They piloted the manned spaceflights of the Mercury program from May 1961 to May 1963.  These seven original American astronauts were Scott Carpenter, Gordon Cooper, John Glenn, Gus Grissom, Wally Schirra, Alan Shepard, and Deke Slayton.

List of NASA astronauts in 2013: List of NASA astronauts in 2013, a listing of the U.S. space agency's astronauts by 2013.  In 2013 the latest Astronaut Group, group 21 was selected but they had not graduated yet, but does include those that graduated from NASA Astronaut Group 20 which was selected in 2009

Chief of the Astronaut Office: The Chief of the Astronaut Office is the most senior leadership position for active astronauts at the National Aeronautics and Space Administration (NASA).  The Chief Astronaut serves as head of the NASA Astronaut Corps and is the principal advisor to the NASA Administrator on astronaut training and operations.

Supporting paragraphs: Mercury Seven Deke Slayton
Answer: Donald Kent "Deke" Slayton