Question: Dixit Dominus is a psalm setting by who, which was a German, later British, baroque composer who spent the bulk of his career in London, becoming well known for his operas, oratorios, anthems, and organ concertos?
Context: Bruckner's Psalm 112, WAB 35, is a psalm setting for eight-part double mixed choir and full orchestra.  It is a setting of a German version of Psalm 113, which is Psalm 112 in the Vulgata. The Handel organ concertos Op 7, HWV 306–311, refer to the six organ concertos for organ and orchestra composed by George Frideric Handel in London between 1740 and 1751, published posthumously in 1761 by the printing company of John Walsh.  They were written for performance during Handel's oratorios, contain almost entirely original material, including some of his most popular and inspired movements. Bruckner's Psalm 114, WAB 36, is a psalm setting of verses 1 to 9 of a German version of Psalm 116, which is Psalm 114 in the Vulgata. George Frideric (or Frederick) Handel ( ; born Georg Friedrich Händel ] ; 23 February 1685 (O.S.) [(N.S.) 5 March] – 14 April 1759) was a German, later British, baroque composer who spent the bulk of his career in London, becoming well known for his operas, oratorios, anthems, and organ concertos. Handel received important training in Halle and worked as a composer in Hamburg and Italy before settling in London in 1712; he became a naturalised British subject in 1727.  He was strongly influenced both by the great composers of the Italian Baroque and by the middle-German polyphonic choral tradition. Psalm 146 in A major (WAB 37) by Anton Bruckner is a psalm setting for double mixed choir, soloists and orchestra.  It is a setting of verses 1 to 11 of a German version of Psalm 147, which is Psalm 146 in the Vulgata. George Frideric Handel (23 February 1685 – 14 April 1759) was a German–English Baroque composer who is famous for his operas, oratorios and concerti grossi.  Handel's compositions include 42 operas; 29 oratorios; more than 120 cantatas, trios and duets; numerous arias; chamber music; a large number of ecumenical pieces; odes and serenatas; and 16 organ concerti.  His oratorio "Messiah", with its "Hallelujah" chorus, is among the most famous Baroque works and is a popular choice for performances during the Christmas season.  Among Handel's best-known instrumental works are the Concerti Grossi Opus 3 and 6; "The Cuckoo and the Nightingale", in which birds are heard calling during passages played in different keys representing the vocal ranges of two birds; and his 16 keyboard suites, especially "The Harmonious Blacksmith". Dixit Dominus is a psalm setting by George Frideric Handel (catalogued as HWV 232).  It uses the Latin text of Psalm 110 (Vulgate 109), which begins with the words "Dixit Dominus" ("The Lord Said"). Nisi Dominus is a setting of the Latin text of Psalm 127 (Vulgate 126) by George Friederic Handel.  The name of the piece comes from the first two words (the "incipit") of the psalm, and it is catalogued in the composer's complete works as HWV 238.  It was completed by 13 July 1707, and is one of a number of works he composed in Italy.  It is most likely that" Nisi Dominus" was first performed on 16 July 1707 in the church of Santa Maria in Montesanto, Rome, under the patronage of the Colonna family. The Handel organ concertos Op 4, HWV 289–294, refer to the six organ concertos for chamber organ and orchestra composed by George Frideric Handel in London between 1735 and 1736 and published in 1738 by the printing company of John Walsh.  Written as interludes in performances of oratorios in Covent Garden, they were the first works of their kind for this combination of instruments and served as a model for later composers. Psalm 110 (Septuagint No. 109) is from the Book of Psalms.  It refers in the general sense to a King ruling over the enemies of the Israelites and is regarded by Jews and Christians as referring to the Messiah.  Because this Psalm is prominent in the Office of Vespers, its Latin text, Dixit Dominus, has particular significance in music, having been set by Marc-Antoine Charpentier (in 1689), George Frideric Handel (1707), Leonardo Leo (in 1741 and 1742), Claudio Monteverdi (1610 and 1640), Wolfgang Amadeus Mozart (1779 and 1780), Giovanni Battista Pergolesi (1732), Nicola Porpora (1720), Alessandro Scarlatti (1700), Tomás Luis de Victoria (1581) and Antonio Vivaldi (twice in 1715), among others.
Answer: George Frideric Handel