It's possible this has been addressed in the new Quizzes.Next feature, but there aren't any guides I can find mentioning any expansion of the quiz response settings in the new quizzes feature and I haven't found these settings myself either. With the current version of quizzes, the settings in the image directly below the quiz should indicate it is locked down so students shouldn't be able to figure out what the correct answers are until May 17th at 12:00 am
However, with the setting above students can see that they scored full points on a question and what their answer was. This is essentially the same thing as showing them that they chose the correct answer, since it shows them how many points the question is out of and what they scored  in addition to what answer they chose .
The default should be if an instructor doesn't want students to see the correct answers until a certain time, students shouldn't be able to see what they scored on a question and see what answer option they provided on a question. I can see this sabotaging quizzes that have more than one attempt, since students will be able to go back into the first attempt and pull out which questions they received credit for.
Ultimately the concern here is it has forced instructors into a binary choice. Either they choose the "Let Students See Their Quiz Responses" option and provide more information than they are comfortable showing students OR they leave that option unchecked and leave their students out in the dark out of concern for the integrity of their questions. If Canvas quizzes can have a second feedback date layer offering more security to their questions, more instructors will be able to open up different layers of their quiz at different times to provide the best learning experience for their students.
| Comments from Instructure|
Please take a look at the Canvas Release Notes (2018-10-06): Quizzes.Next section for partial completion of this idea.