In the 2014 film John Wick, the crime lord who employs the assassins is Viggo Tarasov.
Viggo, played by Michael Nyqvist, is a powerful Russian crime boss and John Wick’s former employer. Years before the film begins, Viggo gave John an “impossible task” so that he could leave criminal life and marry Helen. John completed it, becoming a legendary assassin before retiring.
The plot resumes when Viggo’s son, Iosef Tarasov, steals John’s car and kills his puppy. Viggo understands exactly what this means: John will return to the underworld, and the consequences will be severe. Viggo responds by ordering assassins to kill John and placing a bounty on him.
The names in the answer choices refer to different characters. Iosef is Viggo’s reckless son, Marcus is John’s former mentor and friend, Charlie is a cleaner, and the crime lord himself is Viggo Tarasov. The character is therefore a single, canonical answer for the question.