Coding End of Survey Scoring

I've done something similar in the past using a combination of scoring and embedded data elements in the survey flow.
First, you could create a scoring category for each of the 4 block topics. For each category, assign a scored value of 1 for the correct answers and 0 for the incorrect options -- then your scored sum will equal the number of correct responses in that particular category (e.g., if Topic 1 as 3 questions and someone gets 2 correct answers, the scored value for that category will be 2). Here's what the scoring would look like for one category (repeat for each of the 4 categories):
Then in the survey flow, create a new embedded element at the end of your survey flow (or if you plan to show the scores earlier in the survey, be sure to move the element to immediately follow the block of relevant questions). Create a new variable called "Topic 1 Score" and set it to equal a mathematical operation that calculates the score based off of the scored value for Topic 1 (use piped text for that value, but watch your syntax when using it within a math operation!). The equation will be [piped text for scored value] / [total number of questions in that topic] * 100, which would give you the percentage of items they got correct. That might look something like:
Once these variables are created in your survey flow, you can pipe them into your survey (insert piped text of the embedded variable) to show the value to the respondent. You might want to consider creating a custom end message for the survey that will display these values once the survey is submitted to ensure they submit their responses. Here's what that might look like:
Hope this helps!!
-Erin