How must a corporation establish its principal office?

The correct choice indicates that the principal office of a corporation must be located in the Philippines, as specified in the Articles of Incorporation. This requirement is significant because it establishes the legal domicile of the corporation, which is where it is officially registered and recognized for legal matters. The Articles of Incorporation serve as the foundational document of the corporation, outlining critical information, including the location of its principal office, which must be within the jurisdiction of the country where the corporation is formed. This ensures compliance with local laws and regulations governing businesses in the Philippines, as well as facilitating administrative processes, such as tax matters and legal correspondence.

Other options suggest various possibilities, such as being located in any country or at any random location and imply flexibility that is not permissible under the Revised Corporation Code. The requirement for a principal office in the Philippines ensures that the corporation can be held accountable and can engage with the legal system effectively. Additionally, the lack of requirement for a physical branch in each province underlines the flexibility businesses have in choosing their operational strategy while still maintaining a designated legal address.