La Juive (] ) ("The Jewess") is a grand opera in five acts by Fromental Halévy to an original French libretto by Eugène Scribe; it was first performed at the Opéra, Paris, on 23 February 1835.
The Toulon Opera (L'opéra de Toulon), inaugurated on 1 October 1862, is the second-largest opera house in France, after the Palais Garnier in Paris, although it opened thirteen years before the Garnier.
 The inaugural performance was "Les Mouquetaires de la reine", a comic opera by Fromental Halévy, followed a few days later by "La Juive", the same composer's most famous opera.
John Cox (born 12 March 1935) is an English opera director.
 Born in Bristol, he was educated at St Edmund Hall, Oxford, and trained at Glyndebourne as assistant to Carl Ebert, and then at the York Theatre Royal and BBC television, made his directing debut with Ravel's "L'enfant et les sortilèges" for the Sadler's Wells company in 1965.
L'enfant et les sortilèges: Fantaisie lyrique en deux parties ("The Child and the Spells: A Lyric Fantasy in Two Parts") is an opera in one act, with music by Maurice Ravel to a libretto by Colette.
 It is Ravel's second opera, his first being "L'heure espagnole".
 Written from 1917 to 1925, "L'enfant et les sortilèges" was first performed in Monte Carlo in 1925 under the baton of Victor de Sabata.
The luthéal is a kind of hybrid piano which extended the "register" possibilities of a piano by producing cimbalon-like sounds in some registers, exploiting harmonics of the strings when pulling other register-stops, and also some registers making other objects, which were lowered just above the strings, resound.
 The instrument became obsolete partly because most of its mechanics were too sensitive, needing constant adjustment.
 The only pieces in the general repertoire to feature the luthéal are "L'enfant et les sortilèges" (1920–25) and "Tzigane" (1924) by Maurice Ravel.
Guillaume et les sortilèges is a 2007 French film directed by Pierre Léon.
La taupe et les papillons ("The Mole and the Butterflies") is an opera by the French composer Étienne Méhul.
 It takes the form of a "comédie lyrique" in one act.
 The libretto is by Ange-Étienne-Xavier Poisson de La Chabeaussière.
 Composed in 1797-1798, it was due to be staged at the Théâtre Montansier in 1799 but political censorship meant the opera was never performed.
Eleanor Greenwood is a graduate of the Royal Academy of Music in London.
 Her debut with Wexford Festival Opera was as Pachole'" in "Maria" Polish Opera by Roman Statkowski.
 She has performed roles including 'Hänsel' in "Hänsel und Gretel", Rosina in Il barbiere di Siviglia, Count Orlofsky in "Die Fledermaus", La Ciesca in "Gianni Schicchi", Endimione in "La Calisto", The Wife in "Paradise Moscow (Cheryomushki)", L'Enfant in "L'Enfant et les Sortileges" and Zerlina"' in "Don Giovanni".
 She has performed roles in the Cunning Little Vixen by Janáček.
 She is the sister of Australian musicologist Andrew Greenwood.
Robert Nagy (March 3, 1929 – November 7, 2008) was an American operatic tenor who had a lengthy and fruitful association with the Metropolitan Opera that lasted for three decades.
 His association with the Met began when he won the Metropolitan Opera National Council Auditions in 1956.
 He mostly portrayed comprimario roles at the Met where his most memorable early role was the Messenger in "Aida"; a role he sang 172 times for the company.
 He notably sang in the world premieres of two operas by Samuel Barber at the Met: "Vanessa" (1958) and "Antony and Cleopatra" (1966).
 He also sang in the company premieres of "Die Frau ohne Schatten" (1966), "Billy Budd" (1978) and "L'enfant et les sortilèges" (1981).
 Although Nagy specialized in supporting roles, he also portrayed several leading parts at the Met, among them Florestan in "Fidelio", Herodes in "Salome", and the Drum Major in "Wozzeck'.
 He remained on the Met roster through the end of the 1987–88 season, performing 1,187 performances with the Met during his thirty years with the company.
Prosper Lucas (4 November 1808, Saint-Brieuc – 2 April 1885, Mennecy) was a French medical doctor, brother of Pierre-Hippolyte Lucas (1814-1899) and specialist in the study of heredity.
 For which he wrote ""Traité philosophique et physiologique de l'hérédité naturelle"" ("Philosophical and physiological treatise on natural heredity"), full title – "Traité philosophique et physiologique de l'hérédité naturelle dans les états de santé et de maladie du système nerveux, avec l'application méthodique des lois de la procréation au traitement général des affections dont elle est le principe.
 Ouvrage où la question est considérée dans ses rapports avec les lois primordiales, les théories de la génération, les causes déterminantes de la sexualité, les modifications acquises de la nature originelle des êtres, et les diverses formes de névropathie et d'aliénation mentale", in two volumes (1847 and 1850), which Charles Darwin described in "The Origin of Species" (1859) as "the fullest and the best on this subject".

Question: Which of the following is an opera in one act: L'enfant et les sortilèges or La Juive?
Answer: L'enfant et les sortilèges