Read the text and answer the question. "Leonardo da Vinci was an Italian polymath of the High Renaissance who was active as a painter, draughtsman, engineer, scientist, theorist, sculptor, and architect. He was born on April 15, 1452, in Vinci, Italy. His most famous painting is the Mona Lisa, which he started in 1503." What year did Leonardo da Vinci start painting the Mona Lisa?
A) 1452