This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

The first elected head of government was Cuauhtémoc Cárdenas. Cárdenas resigned in 1999 to run in the 2000 presidential elections and designated Rosario Robles to succeed him, who became the first woman (elected or otherwise) to govern Mexico City. In 2000 Andrés Manuel López Obrador was elected, and resigned in 2005 to run in the 2006 presidential elections, Alejandro Encinas being designated by the Legislative Assembly to finish the term. In 2006, Marcelo Ebrard was elected for the 2006–2012 period.
Who was elected to be the head of government in 2006?