3 Number the countries from 1 to 3 (very big, small number of people).

The numbering depends on the context of the map, which is not provided. However, based on general knowledge:

• 1. China (very big population)
• 2. USA (big population)
• 3. Australia (small number of people)

If the checkboxes were meant to be selected, they are currently unmarked. Assuming the intention was to identify the largest population among the options:

The USA