Which Guanajuato-born muralist painted the massive 'March of Humanity' polyforum in Mexico City, a 2,400-square-metre mural wrapping the interior and exterior of a diamond-shaped building?

• A Jose Clemente Orozco
• B Rufino Tamayo
• C Juan O'Gorman
• D David Alfaro Siqueiros ✓

Siqueiros completed the Polyforum Siqueiros in the 1970s, the world's largest mural at the time, using his signature industrial paints and dynamic perspective.