What type of loop guarantees that the code block will run at least once?

The type of loop that guarantees that the code block will run at least once is a Do While Loop. This loop executes the code within its block first, and then checks the condition at the end of the iteration. Because the condition is evaluated after the code block has executed, it ensures that the statements inside the Do While Loop will always run at least one time, regardless of whether the condition is true or false initially.

In contrast, a For Loop and a While Loop check their conditions before executing their code blocks. If the condition is false from the start, the code within these loops may not execute at all. An Infinite Loop, while it might repeatedly execute a code block, does not guarantee execution of the loop's logic just once in the textbook sense, as it is dependent on external conditions to eventually break out of the loop. Thus, the Do While Loop is uniquely positioned to ensure at least one execution of its code block.