Question Type is the type of question you would like. If you want the user to only select one option, then radio question type is usually the best. If you want a short free text entry, choose text question type. Checkbox is used when you want the user to select one or more options. Textarea is for multiple lines of text input.
The checkbox question type allows you to have multi choice questions.
The correct answer can be just one option like radio question type, or you can choose multiple values that must be select to get the question correct.
In the example below, to get the answer correct you need to select both Koala and Kangaroo, which will give a score of 20 points (10 + 10). Any other combination of options will be incorrect.
If you only select one of the correct answers, the overall question is not correct so you still get a score of zero.
If you select the correct answers but select other options too, then your answer is also incorrect (to be correct it must exactly match the correct answers only).