Happy Feet won the Academy Award for Best Animated Feature instead of Pixar’s Cars at the 2007 ceremony.
Cars was nominated for Best Animated Feature at the 79th Academy Awards, which honored films released in 2006. The nominees were Cars, Happy Feet, and Monster House. The award went to Happy Feet, the musical computer-animated film directed by George Miller about an emperor penguin whose unusual dancing becomes important to his community.
Cars received other major recognition, including an Academy Award nomination for Best Original Song for “Our Town,” written by Randy Newman. The song did not win; “I Need to Wake Up” from An Inconvenient Truth took that award.
Ratatouille was not a nominee at that ceremony because it was released in 2007 and competed at the following year’s awards. The Incredibles had been eligible earlier, for the 2004 film year. Those timing differences explain why they are not the correct answer here.