What characterizes a while loop?

A while loop is characterized by its ability to repeatedly execute its body as long as a specified condition evaluates to true. The key aspect of a while loop is the conditional check that occurs before each iteration; if the condition is true, the loop continues to run, allowing the program to perform repetitive tasks based on dynamic criteria. This makes while loops particularly useful for scenarios where the number of iterations is not predetermined, such as reading user input until a specific entry is made or processing elements of a data structure until a particular condition is met.

The other options describe characteristics that do not accurately depict the functionality of a while loop. For example, executing a specified number of iterations would align more closely with a for loop, while ensuring at least one execution pertains to a do-while loop. Lastly, a while loop operates when the condition is true, not false, thus reinforcing why the third option correctly defines its behavior.