Bonjour Lynn,
In my experience Kwiziq will give alternative answers.
For example, for the first sentence I wrote: "Est-ce que je vais tout droit ?" Kwiziq marked it right and listed the other correct answers: "Je vais tout droit ?"; or "Vais-je tout droit ?"
My first inclination for the translation to "...I am turning carefully." was "...je tourne doucement." but I wrote "prudemment" instead because Collins dictionary gave the example of "Conduisez prudemment !" My answer was marked as correct and that is what Kwiziq wrote, too, (ie. "prudemment"). But, you can see in the paragraph above that "doucement" is used. I have found that it is not uncommon for the paragraph in the final results to differ somewhat from the answers given during the exercise.
You can always look up the different synonyms in various dictionaries and come to your own conclusion. (Sometimes a synonym may not be used in the same context.) Or, you can always pose your question here.
In the end it is really up to you as to how to grade yourself. For example, I don't count off for punctuation, because it is sometimes impossible to know whether or not there is a comma, a period, an exclamation mark, etc.
Keep in mind that the goal is to learn and expand your vocabulary and understanding of and French grammar and expressions not the grade. I don't think there is even a record kept of them for these self-grading exercises.
And, don't forget you can repeat these exercises as many times as you feel you need to.
Hope this helps.
Bonne Continuation !