Which is correct for pluralizing initials?

Which is correct for pluralizing initials?

• A. ABC's
• B. ABCs
• C. ABCC's
• D. ABCCs

Answer: (B)

When you pluralize initials, you typically treat the letters as a unit and add an ordinary “s” at the end, with no apostrophe. This turns the sequence into a pronounceable word and signals plural by simple addition, not possession or a contraction. That’s why the standard form is ABCs—the letters stay in their usual order and the final s is just the plural marker. Using an apostrophe as in ABC's signals possessive (or is a nonstandard plural in some styles), which isn’t the conventional way to form plurals of initials. So ABCCs would be a valid plural in strict form, but ABCs is the more natural, widely accepted choice for the plural of initials, and is the form you’ll see most often in writing.