| Clue | Source | Date |
|---|---|---|
| *Binary inquiry | Universal | 17 Apr 2025 |
| It has only two possible answers | LA Times Daily | 24 Oct 2017 |
| It has only two possible answers | The Washington Post | 24 Oct 2017 |
| It has only two possible answers | ||
| Simple proposal | Wall Street Journal | 14 Sep 2016 |
| "Will you marry me?" is one | ||
| "Will you marry me?" is one |