Which text in the passage shows the writer’s bias?

The Mona Lisa is one of the most talked about paintings in the history of art. It is the only painting which is undisputedly believed to be painted by Leonardo da Vinci. It was sold to the king of France for 4,000 gold coins back when da Vinci was alive. There is a lot of debate about the subject of the painting and, to date, there is no reliable information about the woman featured in the Mona Lisa. It has baffled historians and art critics over the ages. However, it can be said that the woman was very important to da Vinci. It could be someone he loved.

Regardless of the subject of the painting, most people cannot deny that the painting itself is a true marvel. Da Vinci was the world’s greatest genius. He mastered nineteen professions. It’s a feat no ordinary man could accomplish easily, if at all.