How To Make Clickable Text In Minecraft

You can do this using the /tellraw command. The syntax is:

/tellraw <player> <raw json message>

For example, to have a command that activates on click, try running this:

/tellraw @a {"text":"Click this!","clickEvent":{"action":"run_command","value":"/say Hello!"}}

That has a "clickEvent" of type "run_command" with a value of the command to be run. There's a lot of different things you can do with JSON: displaying scoreboard objectives, selectors, items, achievements, entities, different text formatting, etc.

Here's a more complex command with the Yes/No choice and output you wanted:

/tellraw @p ["",{"text":"Yes","color":"green","bold":"true","clickEvent":{"action":"run_command","value":"/tellraw @p {\"text\":\"Confirmed!\",\"color\":\"green\"}"},"hoverEvent":{"action":"show_text","value":{"text":"","extra":[{"text":"Confirm","color":"green"}]}}},{"text":"/","color":"dark_gray","bold":"false"},{"text":"No","color":"red","bold":"true","clickEvent":{"action":"run_command","value":"/tellraw @p {\"text\":\"Cancelled\",\"color\":\"red\"}"},"hoverEvent":{"action":"show_text","value":{"text":"","extra":[{"text":"Cancel","color":"red"}]}}}]

You may want to learn more about the raw JSON text format, or use a JSON generator.