A: You can create multiple-choice quizzes with with a total score and explainations for the correct answers at the end of the quiz. This can be achieved by assigning score for each option (e.g. A=1, B=2, C=3 etc in each question) using Calculator. Also, you can show relevant thank you screens based on the total scores using visibility logic.

Show Thank you screen 1 - When Total score is between 1-5
Show Thank you screen 2 - When Total score is between 6-10
Show Thank you screen 3 - When Total score is between 11-15

Help - https://help.getformly.com/en/articles/9317047-create-a-quiz

Also, you can send conditional email notifications based on score.
https://help.getformly.com/en/articles/9236720-email-notifications

Note - Variables/category wise score or automatically show the results based on the most selected option (Mostly A's, B's etc) will be available by next week.