Which definition best describes a "class" in programming?

A class in programming is best understood as a blueprint for creating objects. This means that a class defines the properties (attributes) and behaviors (methods) that the objects created from it will have. When a class is instantiated, it allows for the creation of individual objects that follow the structure and functionality defined by that class.

For example, if you have a class called "Car," it might define attributes like color, model, and year, as well as methods like drive and stop. Each specific "Car" object created from that class can have its own values for these attributes and utilize the methods as specified.

The other choices do not accurately reflect the concept of a class. A single instance of an object refers to an object itself, rather than the class. A method for data input describes a function or procedure, which is not the same as a class definition. An executable program refers to a standalone application, which also does not represent the concept of a class in programming. Therefore, the definition that identifies a class as a blueprint for creating objects encapsulates its purpose and functionality accurately within object-oriented programming.