Question: What is the nationality of a traditional healer who treated the West Ham United right back from Argentina?

Context paragraphs:
Mariana Kovacevic: Mariana Kovacevic is a Serbian traditional healer who has specialized in the use of horse placenta treatment to heal athletes.  During the duration of the 2012 African Cup of Nations in Gabon and Equatorial Guinea she used the horse placenta treatment to heal Ghana's Asamoah Gyan, who had been injured and was supposed to be off football for four weeks.  She is reported to have nursed him back to health in four hours.  She was also reportedly enlisted by the Serbia during the world of 2010 in south Africa.  Other footballers who are reported to have been treated by Mariana include Pablo Zabaleta, Vincent Kompany, Nigel de Jong and Robin Van Persie of Manchester United.  There has been some doubt as to whether Mariana's therapies work.  But more footballers are turning to her for help.

Ernie England: Ernie England (3 February 1901 – 22 February 1982) was an English footballer who played for Sunderland as a full back.  He made his debut for Sunderland on 27 December 1919 against Manchester City in a 1–0 defeat at Hyde Road.  Overall, at his time at Sunderland he made 335 league appearance scoring no goals, though he scored 3 own goals, before joining West Ham United in 1931.  He made his West Ham debut on 3 January 1931 in a 5-5 against Aston Villa.  Making only five appearances for West Ham he left to join Mansfield Town, for whom he made over 150 appearances.  In 1936 he joined Frickley and became club captain.

Freddie Sears: Frederick David "Freddie" Sears (born 27 November 1989) is an English professional footballer who plays as a forward for Ipswich Town.  He started his career with his local club West Ham United at the age of eleven, progressing through the West Ham United Academy.  He made a scoring first-team debut in March 2008 when he netted the winner against Blackburn Rovers after coming on as a second-half substitute.  Sears made over 50 first-team appearances for West Ham, but never held down a regular starting position.

Pablo Zabaleta: Pablo Javier Zabaleta Girod (] ; born 16 January 1985) is an Argentine professional footballer who plays as a right back for West Ham United and the Argentina national team.  Zabaleta can operate on both sides of the pitch as a full back and is known for his tenacious style of play, and has captained his club on numerous occasions.

Mark Noble: Mark James Noble (born 8 May 1987) is an English footballer who plays as a central midfielder and is captain of West Ham United.  He has played almost all his youth and first team football for West Ham apart from two short loan spells, at Hull City and Ipswich Town.  He has played for England at U16, U17, U18, U19 and U21 levels.  He captained the U21 side, scoring three goals in 20 appearances.  Noble is the longest serving player in West Ham's current squad, having been in the first team since 2004.  He is West Ham's first-choice taker for penalty kicks and has won the club's Hammer of the Year trophy twice.

World Cup Sculpture: The World Cup Sculpture, or simply The Champions, is a bronze statue of the 1966 World Cup Final located near West Ham United Football Club's Boleyn Ground (Upton Park) stadium in the London Borough of Newham, England.  It depicts a famous victory scene photographed after the final, held at the old Wembley Stadium in London, featuring Bobby Moore, Geoff Hurst, Martin Peters and Ray Wilson.  It was the first and only time England had won the World Cup, and England captain Moore is pictured held shoulder high, holding the Jules Rimet Trophy aloft.  Jointly commissioned by Newham Council and West Ham United, it stands at the junction of Barking Road and Green Street, near the Boleyn Ground.  It commemorates West Ham's contribution to the victory, with Moore, Hurst and Peters having all been West Ham players at the time of the 1966 World Cup.  Sculpted by the Royal Sculptor Philip Jackson, it was unveiled in 2003 by Prince Andrew, president of the Football Association.  Jackson went on to also sculpt the statue of Bobby Moore unveiled at the new Wembley when it opened in 2007.

West Ham Poor Law Union: West Ham Poor Law Union was a poor law union established on 31 May 1836.  It initially covered the parishes of East Ham, Leyton, Little Ilford, Walthamstow, Wanstead, West Ham and Woodford, with the addition of Cann Hall from 1894 onwards.  This meant that it straddled several other urban districts, county boroughs and municipal boroughs set up later in the 19th century and early in the 20th century - West Ham (West Ham), East Ham (East Ham, Little Ilford), Wanstead (Wanstead), Woodford (Woodford), Leyton (Leyton, Cann Hall) and Walthamstow (Walthamstow).  It ran the West Ham Union Workhouse.

West Ham United F.C. Under-23s: West Ham United F.C. Under-23s, formerly West Ham United F.C. Under-21s is the most senior of West Ham United's youth teams.  The Under-23 team is effectively West Ham United's second-string side, but is limited to three outfield players and one goalkeeper over the age of 23 per game following the introduction of new regulations from the 2012–13 season.  They play in Premier League 2 and also compete in the Checkatrade Trophy.

West Ham United F.C. Reserves: The West Ham United Academy is recognised as one of the most successful academies in modern football, hence its nickname the Academy of Football.  The introduction of the FA's new Academy system in 1998 has placed even more emphasis on the developing of young homegrown players and today the youth system at West Ham is more important than it has ever been.  With the influx of many foreign players in the Premier League during modern times, West Ham United has been regarded as one of the few remaining clubs in top flight to continue producing and playing homegrown English players.

Danny Williamson (footballer): Daniel 'Danny' Williamson (born 5 December 1973 in West Ham, London) is an English retired professional footballer who was a product of the West Ham United academy and played for West Ham United and Everton in the 1990s.  He played in midfield.

Supporting paragraphs: Mariana Kovacevic Pablo Zabaleta
Answer: Serbian