How is JSON primarily structured?

JSON, or JavaScript Object Notation, is primarily structured with key/value pairs, which makes option three the correct choice. This structure allows data to be organized in a way that is both human-readable and easily interpretable by machines. In JSON, data is represented as an object, enclosed in curly braces {}, where individual entries consist of keys (strings) associated with values (which can be strings, numbers, arrays, objects, booleans, or null).

Additionally, JSON can include arrays, represented by square brackets [], which can contain multiple values or objects. This allows for a rich and nested data representation, giving JSON robustness in data interchange formats used in web services, APIs, and configurations.

The other options lack the specific structure inherent in JSON. Arrays alone do not encompass the key/value pair concept central to JSON syntax. Describing JSON as unstructured data is misleading, as it has a specific format and hierarchy. While JSON can be stored in a flat file, this does not define its structure; rather, it refers to how it may be saved as text. Thus, understanding JSON’s key/value structure is fundamental for anyone working with data interchange in web technologies.