The expression \( p^m \cdot p^n \) can be simplified using the laws of exponents. According to the product of powers property, when we multiply two expressions with the same base, we add the exponents:
\[ p^m \cdot p^n = p^{m+n} \]
None of the provided answer choices exactly state \( p^{m+n} \), but when matched with the format of the choices, it would correspond most closely to \( p^{m+n} \).
Therefore, the answer is:
None of the options listed are correct. The correct result should be \( p^{m+n} \).