Captain Jack Sparrow redecorates the Black Pearl and wants to open it up to the public with these prices, for 10, a tourist can visit the 1st deck, for 20, a tourist can visit the whole ship. Which security service can be implemented to enforce these rules?
1) Ticketing system with different prices for each deck
2) Security guards at each entrance
3) Surveillance cameras throughout the ship
4) Metal detectors at the entrances