{
  "kind": "question",
  "title": "Dentist check-up: which slot?",
  "text": "Dr. Nowak has three openings next week. All 30 minutes, 10 min by tram. Your calendar is free for each.",
  "controls": [
    {
      "type": "button",
      "id": "tue_0830",
      "label": "Tue 11 Nov, 8:30"
    },
    {
      "type": "button",
      "id": "thu_1000",
      "label": "Thu 13 Nov, 10:00",
      "style": "primary"
    },
    {
      "type": "button",
      "id": "fri_1630",
      "label": "Fri 14 Nov, 16:30"
    },
    {
      "type": "button",
      "id": "none",
      "label": "None of these"
    }
  ]
}