Question: Princess Wilhelmine Ernestine of Denmark was the third daughter of what king also known as Frederick II?
Context: Princess Hedwig of Denmark (5 August 1581 – 26 November 1641) was the youngest daughter of King Frederick II of Denmark and Sophie of Mecklenburg-Güstrow, and Electress of Saxony from 1602 to 1611 as the wife of Christian II. Princess Marie Gabriele of Luxembourg, Countess of Holstein-Ledreborg (given names: "Marie Gabrielle Aldegunde Wilhelmine Louise"; born 2 August 1925) is the third daughter and fourth of the six children of Grand Duchess Charlotte of Luxembourg and her husband Prince Félix.  She is the younger sister of former Grand Duke Jean of Luxembourg and thus a paternal aunt to the current Grand Duke, Jean's son Grand Duke Henri.  In 1951 she married Danish Count Karl Johan Ludvig, 7th Count of Holstein-Ledreborg (2 October 1919 – 25 June 2001), Roman Catholic; the couple were married for 50 years until his death in 2001.  Together, they had seven daughters. Princess Vilhelmine Marie of Denmark and Norway (Danish: "Vilhelmine af Danmark" ; German: "Wilhelmine von Dänemark" ) (18 January 1808, Kiel, Duchy of Schleswig – 30 May 1891 in Glücksburg, Schleswig-Holstein, Prussia) was the youngest daughter of Frederick VI of Denmark and his wife and first cousin Marie Sophie of Hesse-Kassel.  Her paternal grandfather, Christian VII of Denmark, had major psychological problems and as result, her father had been acting as Regent since 1784.  Within two months of her birth, Vilhelmine Marie's grandfather died of a cerebral aneurysm and her father ascended as king.  At the time of her death, she was the last surviving grandchild of Christian VII. Princess Thyra of Denmark and Iceland (Thyra Louise Caroline Amalie Augusta Elisabeth; Copenhagen, 14 March 1880 – Copenhagen, 2 November 1945) was the sixth child and third daughter of Frederick VIII of Denmark and his wife, Princess Louise of Sweden and Norway. Mary of England, Scotland and Ireland (8 April 1605 16 September 1607) was the third daughter and sixth child of James VI and I, the first king of a unified England, Scotland and Ireland, by Anne of Denmark, daughter of Frederick II of Denmark and sister of Christian IV of Denmark; her birth was much anticipated.  She developed pneumonia at 17 months and died the following year. Frederick III (Danish: "Frederik" ; 18 March 1609 – 9 February 1670) was king of Denmark and Norway from 1648 until his death in 1670.  He also governed under the name Frederick II as diocesan administrator (colloquially referred to as prince-bishop) of the Prince-Bishopric of Verden (1623–29 and again 1634–44), and the Prince-Archbishopric of Bremen (1635–45). The Temple of Friendship (German: "Freundschaftstempel" ) is a small, round temple in the western part of Sanssouci Park in Potsdam.  It was built by the Prussian king Frederick II in memory of his favorite sister, Markgravine Wilhelmine of Bayreuth, who died in 1758.  The temple was built south of the park's main boulevard between 1768 and 1770 by architect Carl von Gontard, complementing the Temple of Antiquities, which lies due north of the boulevard on an axis with the Temple of Friendship. Wilhelmine Ernestine of Denmark and Norway (Danish: "Vilhelmine Ernestine" , German: "Wilhelmine Ernestine" ) of Denmark (born 20 or 21 June 1650 – died 22 or 23 April 1706) was an Electress of the Palatinate.  She was the third of five daughters of King Frederick III of Denmark and Sophie Amalie of Brunswick-Lüneburg. Frederick of Pettorano ("c".  1212/3 – after 1240) was the eldest illegitimate son of Frederick II, king of Sicily and Germany.  He was born on Sicily to an Italo-Norman noblewoman after his father's first marriage to Constance of Aragon.  This mistress's name is unknown, but she came from a family of Norman counts on Sicily and had a relationship with the teenage Frederick between 1211 and 1212.  Their relationship ended when King Frederick went to Germany and in 1213 took up with another woman, a certain Adelaide.  Besides Frederick of Pettorano, Frederick II probably named two other sons after himself: another illegitimate son, Frederick of Antioch, and a legitimate son by his wife Isabella.  This last is known only by the initial "F." and died young. Princess Augusta of Denmark (8 April 1580 – 5 February 1639) was the third daughter of King Frederick II of Denmark and Sophia of Mecklenburg-Güstrow, and Duchess of Holstein-Gottorp as the wife of Duke John Adolf.  She was politically influential during the reign of her son, Duke Frederick III.
Answer: King Frederick III of Denmark