What is the sequence for First-Class Mail machinable letters?

The correct answer reflects the proper sequence for First-Class Mail machinable letters, which is "AADC - origin." This sequence is commonly used in the sorting and processing of these letters.

In this context, "AADC" indicates the specific categories and sequencing related to the origins of the letters. The "AA" represents a specific type of address, while the "DC" signifies the designation for machinable mail items that are suitable for automated processing. This system is crucial for efficient sorting and delivery, ensuring that machinable letters are categorized and handled accordingly from their origin points.

Understanding this sequence is important for mailers to ensure their letters are processed in the most efficient manner possible, aligning with the United States Postal Service's practices for First-Class Mail. Other sequences mentioned in the choices do not relate to the first-class machinable letter classification or sequence in the same way.