The correct answer is B) generally similar in scope to the inspection required for certification, but in less detail. This is because the regulations require that at least one re-inspection be conducted on each vessel holding a Certificate of Inspection that is valid for two years. This re-inspection must be held between the 10th and 14th months of the certificate's duration period, and it must be generally similar in scope to the original inspection required for certification, but in less detail. The other answer choices are incorrect because A) the re-inspection is not equivalent to the original certification inspection, C) the inspector does not have full discretion over the scope of the re-inspection, and D) the re-inspection must be in no less detail than the original certification inspection.