45.
The answer is: D
Explanation
Answer: D - Roger Federer
Roger Federer defeated Marin Čilić in the final, 6–2, 6–7, 6–3, 3–6, 6–1 to win the Men's Singles title at the 2018 Australian Open.
Historic significance of this win:
It was his record-equalling sixth Australian Open title (tied with Roy Emerson and Novak Djokovic), and his record-extending 20th Grand Slam title overall. At 36 years, 5 months and 20 days old, Federer was the oldest man to win a major singles title since Ken Rosewall in 1972.
2018 Australian Open - Complete Champions:
| Event | Champion |
|---|---|
| Men's Singles | Roger Federer |
| Women's Singles | Caroline Wozniacki |
| Men's Doubles | Oliver Marach / Mate Pavić |
| Women's Doubles | Tímea Babos / Kristina Mladenovic |
Why other options are wrong:
- Marin Cilic - Was the runner-up, defeated by Federer in the final. Very deliberate trap.
- Novak Djokovic - Was not even in the 2018 final. Was recovering from injury.
- Rafael Nadal - Did not win. Withdrew from the semifinal due to injury.
Federer's Australian Open titles - quick reference:
| Year | Opponent in Final |
|---|---|
| 2004, 2006, 2007, 2010, 2017, 2018 | Various |