Explanation: Commercial operator licenses, like the First Class Radiotelegraph Operator license, are renewed directly with the Federal Communications Commission (FCC). FCC regulations stipulate a specific process: the licensee must submit Form 756 (Application for Renewal of Commercial Radio Operator License), a copy of their current license, and the appropriate fee. This application must be filed within the last year of the license's five-year term. Option A is incorrect because the renewal window is longer than 90 days, and a specific form is required. Option B is incorrect as Commercial Operator Licensing Examination Managers (COLEMs) administer examinations, but license renewals are sent directly to the FCC, not through a COLEM. Option D introduces a fictional "Radio telegraphy Proficiency Testimonial" and an incorrect form (Form 739); such a testimonial from a ship's master is not an FCC requirement for renewal.