When designing your domain model, define an entity for each thing. The things you mentioned are a 'line of guidance', 'business' and a 'question'. 'section' might be the same as 'line of guidance'. Since 'line of guidance' has a series of 'question's, they will be related with a 1-many relation.
Controls Assessment is not a thing, it is a proces. For this, you will end up having a page with the line of guidance and the questions and a button for processing the answers. Your entity 'Controls Assessment' might only store attributes about logging the proces, like done by who, datetime, maybe a number etc.