As of May 2010, who was the foreign minister of the European Union?

The correct choice is: “Baroness Ashton”

Under the Lisbon Treaty (in force from 1 December 2009) the EU created the post of High Representative of the Union for Foreign Affairs and Security Policy, popularly called the EU “foreign minister”. The first holder was the British politician Catherine Ashton (Baroness Ashton of Upholland), who served from December 2009 to 2014.

“Massimo D’Alema”, a former Prime Minister and Foreign Minister of Italy, and “David Miliband”, then the UK Foreign Secretary, were both talked of for the post but were not appointed. “Carl Bildt” was the Foreign Minister of Sweden, whose country held the rotating EU Council presidency in the second half of 2009; he was never the EU’s own foreign-policy chief.