1. The difference between regulations and revenue rulings is that _____

a. Revenue rulings are not limited to a given set of facts and regulations are limited

b. Revenue rulings are the direct law-making powers of Congress and regulations are not

c. Revenue rulings require approval by the Secretary of the Treasury; regulations do not

d. Revenue rulings do not have the authority of regulations; regulations are a direct extension of the law-making powers of Congress e. Only regulations are official pronouncements of the National Office of the IRS