At the time of his death, Jye was a shareholder in Grebe Corporation. In valuing the Grebe stock included in Jye's gross estate, the IRS contends that the corporation possessed considerable goodwill. In disputing this contention, which of the following point(s) is/are relevant?

a. The rate of return used by the IRS for the type of business involved is too high

b. Jye was not an employee of Grebe but was merely a passive investor.

c. To provide financing, Grebe has been obtaining its working capital from banks at a market rate of interest.

d. Average net profit figures include large gains from unrelated investments.