What does a programming constant help ensure?

A programming constant helps ensure unchangeable values during execution. By definition, a constant is a fixed value that does not change throughout the execution of the program. This means that once a constant is defined, its value remains the same, providing reliability and consistency in the program. This trait is particularly useful when there is a need to prevent accidental alterations to values that should remain consistent, such as mathematical constants (e.g., pi) or configuration settings.

The other options do not accurately represent the primary function of a constant. Flexibility implies adaptability, which contradicts the purpose of a constant. Faster execution may depend more on the overall algorithm or system performance rather than the use of constants specifically. Lower memory usage is not inherently guaranteed by constants, as memory usage is influenced by various factors, including data types and structures used throughout the program.