What statement correctly completes the loop in this code snippet?

The correct choice is based on the intended functionality of the loop within the code snippet. In many programming scenarios, especially when dealing with financial calculations or iterative processes over time, you want to control how a variable changes within a loop to achieve a specific outcome.

If the purpose of the loop is to decrement a certain variable—perhaps to represent a reduction in years or to adjust a balance downwards—then using 'years--' would logically fit within the context of the loop. This operation decreases the 'years' variable by one with each iteration, allowing the loop to eventually reach a termination condition that is based on a countdown.

In loops, controlling the increment or decrement of variables is crucial to ensure the loop functions as intended. The option of decrementing 'years' increases the likelihood that the loop will exit correctly once the stopping condition is reached. On the other hand, incrementing 'years' or making changes to 'balance' might lead to infinite loops or incorrect calculations, depending on how these variables are used in the overall algorithm or logic of your code. Therefore, decrementing 'years' aligns with typical practices in controlled iterations where a target limit is being approached in reverse.