Which Revenue Ruling primarily addresses discount factors in valuation?

Revenue Ruling 77-287 is significant in the field of business valuation, particularly regarding discount factors. This ruling provides guidance on how to determine an appropriate discount rate to apply to future income streams. It emphasizes the need to consider both the risk associated with the cash flows and the time value of money when performing a valuation.

This ruling discusses the importance of selecting a discount rate that accurately reflects the risk profile of the business being valued, including specific considerations for different industries and economic circumstances. By addressing discount factors, this ruling has implications for how valuators calculate the present value of expected future cash flows, which is a central aspect of valuation methodologies.

The other rulings mentioned do not specifically focus on discount factors in the same comprehensive manner. While they cover other pivotal aspects of valuation and tax implications, they do not primarily address the intricacies of discount rates as extensively as Revenue Ruling 77-287 does. This makes option B the correct answer for the question pertaining to discount factors in valuation.