Final answer:
Revenue rulings are first published in the weekly Internal Revenue Bulletin and then compiled and republished semi-annually in the Cumulative Bulletin. The I.R.B provides immediate availability, while the C.B offers a more permanent archive.
Step-by-step explanation:
The citations for revenue rulings refer to different bulletins based on their publication timeline. Option C is the correct answer. Revenue rulings are first released in the Internal Revenue Bulletin (I.R.B.), which is published weekly. These bulletins serve as a disseminating tool for the rulings, providing immediate notification to the public. Subsequently, these rulings are compiled, along with other important IRS pronouncements, and are published semi-annually in the Cumulative Bulletin (C.B.). The C.B. serves as a more permanent and easily referenced compilation of the rulings that were issued over the course of six months. This two-step publication process ensures that rulings are both promptly made available to taxpayers and tax professionals, and also archived in an organized and accessible format for future reference.