13. A patentee holds a valid patent for a chemical formulation requiring the use of "alkaline earth metal" as a core stabilizing element. A competitor later manufactures a competing product substituting the "alkaline earth metal" with a specific silicate compound. Compared with the patent concerned, while the product does not fall within the literal scope, it functions substantively the same, known to a skilled person at the time of infringement. Under Taiwan's patent infringement assessment guidelines, which legal framework should the court invoke to determine whether infringement is established? (A) The Prosecution History Estoppel (B) The Compulsory Licensing Provisions to permit third-party usage based on public interest. (C) The Literal Infringement Test to confirm absolute textual identity between the claim and the accused product. (D) The Doctrine of Equivalents to prevent the competitor from avoiding liability through insubstantial variations.