The correct response to the question is "primitive data structure."
A primitive data structure is a basic type of data that stores a single value, such as an integer, float, or character. It must contain some value and cannot be null. However, in the context of your options and wording, it seems that the specific type (like "float") might not hold, as primitive data structures in general can include multiple types.
The best option considering your choices is "primitive data structure" as it caters to the definition of storing a value and not being null.