How do i turn this on? aegis, robin hood, lumberjack, cheese steak jimmy's, natural wonders, resign, to smithereens, torpedo, i love the monkey head, i r winner, montezuma, pandemic, architectivity, cauterize enabled, marco, polo, master builder, black death, woofwoof, wimpywimpywimpy, torpedo2.

This is a list of cheatcodes or microsoft famous Ages of empires 2.

Explanation:

All of these were commands that if put in the Ages of empires 2 send message option would give you access to a certain favorable object or ability. For example: "How do you turn this on? was a command that could be sent in the "insert message" option to get a Shelby cobra with 500HP and long-distance damage by throwing rocks. It was one of the most advantageous heroes in the game. All of these granted different things, gold, stone, wood, visibility, etc.

the answer is:

c. economic output