What major international event did New Zealand host in 2011?

New Zealand hosted the Rugby World Cup in 2011, which is a significant international sporting event that showcases the best rugby teams from around the world. The tournament was particularly important as it marked the first time New Zealand hosted this prestigious event since 1987. The competition featured 20 teams and took place across various venues in New Zealand, fostering a strong sense of national pride and unity. The event was also notable for the enthusiastic support from fans both domestically and internationally, highlighting New Zealand's rich rugby culture and traditions.

The other options do not apply as New Zealand has not hosted the Commonwealth Games, Cricket World Cup, or the Olympics in 2011, which is why they are not the correct choice. The Rugby World Cup stands out for its global reach and significance in New Zealand's sports history, making it the appropriate answer for this question.