12. Under the R.O.C. Patent Act, if a patentee wishes to amend the scope of claims after the grant of the patent, which of the following conditions must be satisfied for the amendment to be legally permissible? (A) The amendment may broaden the scope of claims as long as it is within one year after grant. (B) The amendment is allowed only if the patentee pays an additional annuity fee within six months of the amendment request. (C) The amendment must not substantially enlarge or alter the scope of the claims, and must comply with the requirements of clarity and support by the specification. (D) The amendment can freely introduce new technical features not disclosed in the original specification, provided they improve industrial applicability.