Explanation:

- The Hopman Cup is a mixed-gender team tennis tournament.

- It began in 1989 and is named after Australian tennis player Harry Hopman.

- This tournament is unique as it features teams with both male and female players representing their countries.

- Option 1: Football

- Football is a globally popular sport with major tournaments like the FIFA World Cup.

- It has no connection to the Hopman Cup.

- Option 2: Cricket

- Cricket features major international events like the ICC World Cup.

- There is no association between cricket and the Hopman Cup.

- Option 3: Tennis

- The Hopman Cup is associated with tennis.

- This option correctly identifies the sport related to this tournament.

- Option 4: Hockey

- Hockey is played on grass or artificial turf, with events like the Hockey World Cup.

- The Hopman Cup is not linked to hockey.

- Option 5: Badminton

- Badminton is played indoors with the BWF World Championships as a major event.

- It does not relate to the Hopman Cup.