Answer : 2. "Explorer"
Explanation :

An explorer is someone who travels to unknown places in order to discover new things. A tourist typically travels for leisure or sightseeing rather than exploration. A wanderer refers more to someone who travels aimlessly or without a specific destination in mind. A nomad is someone who moves from place to place, often following traditional routes or patterns, rather than exploring unknown territories. Therefore, "Explorer" best fits the description of a person who travels to unknown places to find out new things.