Answer:
b. Foursquare
Explanation:
Foursquare is a service based on web localization applied to social networks. The geolocation allows locating a fixed or mobile device in a geographical location.
The main idea of the network is to mark specific places where one is and to earn points for "discovering" new places; The reward is the "Badges", a kind of medals, and the "Mayorships", which are won by the people who do the most "check-ins" in a certain place in the last 60 days.
Since the creation of Swarm in May 2015, public check-ins and town halls have been hidden (but verified business owners can request access to that information) in order to evolve as a recommendation engine that suggests interesting places .
