Which of these men is not a famous landscape architect?

Joseph Mallord William Turner (1775—1851), is not a famous landscape architect. He is best known as an English Romantic artist. He is known as 'the painter of light', because of his increasing interest in brilliant colors as the main constituent in his landscapes and seascapes. His works include water colors, oils, and engravings.

André Le Nôtre, Lancelot Brown, and Frederick Law Olmsted were all landscape architects. They are known because their works characterize the natural, planned and unplanned elements, in spectacular garden appearances.

André Le Nôtre (1613—1700) was French and the principal gardener of King Louis XIV of France. He designed the gardens at the Palace of Versailles and the gardens of the château at Fontainebleau, France.

Lancelot Brown (aka "Capability" Brown, 1716—1783) was considered the foremost English master of garden design. His works appear in over 170 gardens surrounding the finest country houses and estates in Britain. They are present at Belvoir Castle, Croome Court, Blenheim Palace, Warwick Castle, Harewood House, Highclere Castle, Appuldurcombe House, Milton Abbey, Kew Gardens, and other locations.

Frederick Law Olmsted (1822—1903) was an American and is regarded as the founder of American landscape architecture. He is best known for designing the grounds of New York City's Central Park, the U.S. Capitol in Washington, D.C., the Biltmore Estate in North Carolina. and the 1893 World's Columbian Exposition in Chicago.