Most questions in SeniorGrowth assessments are single-choice: you can only chose one answer among the options offered. For some of them, there are different choices you can or have to make. The behaviour of the system is a bit different for multiple-choice questions.
To answer multiple-choice questions, you always have to click on the save button before moving on. When you first reach a multiple-choice questions, you can decide to click on Save to leave the options by default.
If you click on any of the options, the "Previous" and "Next" buttons will disappear, leaving you no choice but to click on "Save" (see below).
The Nutrition Intake question is very special in that you will probably have to click on all the options as the default intake for every food category is set to zero portions per week.