- 10 indicates that this rule has been complied with or that it is impossible to do so, that the State may argue that it has not been complied with and, in this case, it must prove the availability, adequacy, appropriateness and effectiveness of the domestic remedies that were not exhausted, all of which shows, once again, that this requirement must have been met previously; that is, before drawing up the petition the relevant parts of which are forwarded to the State precisely so that it may respond to them. Furthermore, Article 30(5) and (6) of the Commission’s Rules of Procedure point in the same direction. Indeed, they establish that “[p]rior to deciding upon the admissibility of the petition, the Commission may invite the parties to submit additional observations, either in writing or in a hearing, as provided for in Chapter VI of the […] Rules of Procedure,” which leaves no margin of doubt that the said “additional observations” must relate to the petition, as it was “lodged” and not constitute a new petition or modify the original one, unless, as is logical, this entails its withdrawal. Consequently, it is undeniable that this response by the State logically and necessarily must relate to the petition that was “lodged” before the Commission, and that it is at that moment, and not afterwards, that the legal proceedings, or the adversarial proceedings, as regards the exhaustion of domestic remedies are instituted. And, for the same reason, it is at that moment that the domestic remedies must have been exhausted or that the petitioner indicates the impossibility of exhausting them. To affirm that those remedies could be exhausted after the petition has been “lodged” and, consequently, notified to the State, would affect the essential procedural balance and would leave the State defenseless, because it could not file the pertinent preliminary objection in time and in due form. It is in this context that the criterion “consistently affirmed [by the Court that] an objection to the jurisdiction of the Court based on the supposed failure to exhaust domestic remedies must be filed at the appropriate procedural opportunity; that is, during the admissibility stage of the proceedings before the Commission” 27should be understood. E. Admissibility of the petition The preceding consideration is also evident from Article 31(1) of the Commission’s Rules of Procedure, which establishes that “[i]n order to decide on the admissibility of a matter, the Commission shall verify whether the remedies of the domestic legal system have been pursued and exhausted in accordance with the generally recognized principles of international law.” This provision requires the Commission to “verify,” that is, to confirm [Note: verificarcomprobar28 in the Spanish text], the filing and exhaustion of the domestic remedies, in order to “decide” on admissibility. And, this is logical, because that decision could be not to admit the petition because such remedies have not been exhausted. This means that, in order to take a decision on the admissibility of the petition, the Commission must verify whether the rule of prior exhaustion of domestic remedies has been complied with and, if not, the corresponding decision would be to declare the petition inadmissible. The essential requisite that enables the Commission to decide on the 27 Case of Cruz Sánchez et al. v. Peru. Preliminary objections, merits, reparations and costs. Judgment of April 17, 2015. Series C No. 292, para. 49. 28 Diccionario de la Lengua Española, Real Academia Española, 23 rd edition, October 2014.