Which boxer, nicknamed 'Canelo', has won world championships in four different weight classes and is considered one of the greatest pound-for-pound fighters of his era?

• A Julio Cesar Chavez
• B Juan Manuel Marquez
• C Marco Antonio Barrera
• D Saul Alvarez ✓

Saul 'Canelo' Alvarez has held titles at super-welterweight, middleweight, super-middleweight and light-heavyweight, becoming the face of boxing globally.