For whatever reason, the Elements of the Periodic Table quiz uses the British "Aluminium" but the American "Cesium". Technically, "aluminum" should be an answer for this quiz, but I didn't include it because it is the correct name in American English. Because of this, I also decided to put "cesium" as a grayed-out answer for consistency, even though it wouldn't be an answer anyway.
Okay, the quiz changed to use "caesium". Even though "aluminum" and "cesium" are correct in American English, I decided to put them in anyway because they're different from the answer in the quiz.