A good explanation helps the reader, by allowing them to paint a clear consecutive image of events in their mind about what's going on withing the context of the story.
make sense?
The word or phrase that best connects the ideas in the sentences in question is D, that is, your anwer would be "in contrast".
The first part of the passage shows that we should have the right to choose sodas or snacks if we want to, we should be given the right to do that. On the contrary, the second part of the passage talks about that sometimes having too many options is not a good thing and it makes us unable to make the right choice.
