Question: Who is Princess Marie Alexandra Of Schleswig-Holstein's maternal grandfather?

Knowledge 1: Princess Marie Alexandra of Schleswig-Holstein
Princess Marie Alexandra of Schleswig-Holstein-Sonderburg-Glücksburg, since 1941 of Schleswig-Holstein (Marie Alexandra Caroline-Mathilde Viktoria Irene; 9 July 1927, Schloss Louisenlund, Schleswig, Schleswig-Holstein, Germany – 14 December 2000, Friedrichshafen, Baden-Württemberg, Germany) was a member of the House of Schleswig-Holstein-Sonderburg-Glücksburg.Marie Alexandra was the fourth and youngest child of Wilhelm Friedrich, Duke of Schleswig-Holstein and his wife Princess Marie Melita of Hohenlohe-Langenburg.Her older brother Peter was the Duke of Schleswig-Holstein and Head of the House of Oldenburg from 10 February 1965 until his death on 30 September 1980. [SEP] Knowledge 2: Princess Marie Melita of Hohenlohe-Langenburg
Princess Marie Melita of Hohenlohe-Langenburg (18 January 1899, Langenburg, Württemberg – 8 November 1967, Munich, Germany) was the Duchess consort of Schleswig-Holstein as the wife of Wilhelm Friedrich, Duke of Schleswig-Holstein.She was the eldest daughter of Ernst II, Prince of Hohenlohe-Langenburg and his wife Princess Alexandra of Saxe-Coburg and Gotha.
Knowledge 1: Princess Marie Alexandra of Schleswig-Holstein
Princess Marie Alexandra of Schleswig-Holstein-Sonderburg-Glücksburg, since 1941 of Schleswig-Holstein (Marie Alexandra Caroline-Mathilde Viktoria Irene; 9 July 1927, Schloss Louisenlund, Schleswig, Schleswig-Holstein, Germany – 14 December 2000, Friedrichshafen, Baden-Württemberg, Germany) was a member of the House of Schleswig-Holstein-Sonderburg-Glücksburg.Marie Alexandra was the fourth and youngest child of Wilhelm Friedrich, Duke of Schleswig-Holstein and his wife Princess Marie Melita of Hohenlohe-Langenburg.Her older brother Peter was the Duke of Schleswig-Holstein and Head of the House of Oldenburg from 10 February 1965 until his death on 30 September 1980. [SEP] Knowledge 2: Princess Marie Alexandra of Baden
Princess Marie Alexandra of Baden(" Marie Alexandra Thyra Victoria Louise Carola Hilda"; 1 August 1902 – 29 January 1944) was a Hessian princess by marriage.
Knowledge 1: Princess Marie Alexandra of Schleswig-Holstein
Princess Marie Alexandra of Schleswig-Holstein-Sonderburg-Glücksburg, since 1941 of Schleswig-Holstein (Marie Alexandra Caroline-Mathilde Viktoria Irene; 9 July 1927, Schloss Louisenlund, Schleswig, Schleswig-Holstein, Germany – 14 December 2000, Friedrichshafen, Baden-Württemberg, Germany) was a member of the House of Schleswig-Holstein-Sonderburg-Glücksburg.Marie Alexandra was the fourth and youngest child of Wilhelm Friedrich, Duke of Schleswig-Holstein and his wife Princess Marie Melita of Hohenlohe-Langenburg.Her older brother Peter was the Duke of Schleswig-Holstein and Head of the House of Oldenburg from 10 February 1965 until his death on 30 September 1980. [SEP] Knowledge 2: Peter, Duke of Schleswig-Holstein
Peter, Duke of Schleswig- Holstein( 30 April 1922 in Schloss Louisenlund, Schleswig, Schleswig- Holstein, Germany – 30 September 1980 in Bienebek, Schleswig- Holstein, West Germany) was the Duke of Schleswig- Holstein and Head of both the House of Glücksburg and the entire House of Oldenburg from 10 February 1965 until his death on 30 September 1980.Peter was the third and youngest son of Wilhelm Friedrich, Duke of Schleswig- Holstein and his wife, Princess Marie Melita of Hohenlohe- Langenburg.He was a great- great- grandson of Queen Victoria through her second son, Prince Alfred.

Answer: Ernst II, Prince of Hohenlohe-Langenburg