"Do you eat rice?"
"米饭" wasn't an option for me, so I had to pick "你吃米吗？" when answering this.
I searched 米 and 饭 in a dictionary and it seems that 米 is (uncooked) rice and 饭 is as food/meal. And 米饭 means cooked rice.
Does 米饭 actually mean 'rice'? , such as if someone wanted to ask or answer about that specific food?
In "你吃不吃米饭？" 不 is used to ask a question: "You eat/not eat rice". It is like choosing a yes/no option in a form.
The you in english is ambigous. Could also mean 你们 but that was not counted as correct.
Indeed it is. But I figured it out that they use 'guys' to distinguish between singular and plural cases: "Do you guys eat rice?"
I at first used you (plural) because in English there is no difference. It marked it wrong.