To simplify 12543, we consider the prime factorization of the number. However, this seems like an incomplete query since there's no operation indicated (like a square root or something similar).
Assuming you intended to find the square root:
\(\sqrt{12543}\) is approximately equal to 112.
None of the given options (625, 125, 5, 25) matches this. Therefore, if you're looking for a direct simplification and there is no further context or operation indicated, it's unclear how to proceed.
Could you please clarify what you mean by "simplification"? Are you looking for a specific operation to perform on 12543?