Statement on Standards for Tax Services No. 1 establishes as a basic principle of providing tax services that the CPA:

a. Must have a good faith belief that the tax return position will be accepted by the IRS.
b. Must have a good faith belief that the tax return position has a realistic possibility of success if challenged by the IRS.
c. Can never recommend a tax position to the client when it is more likely than not to be challenged by the IRS.
d. Can never recommend a tax position to the client without disclosing it to the SEC.

c. Must have a good faith belief that the tax return position has a realistic possibility of success if challenged by the IRS

Explanation:

Statement on Standards for Tax Services No. 1 establishes as a basic principle of providing tax services that the CPA

we know that

Giving assessment administrations is on the standard premise that it has a decent confidence conviction that the government form position can be supported whenever tested

therefore

option c is correct

c. Must have a good faith belief that the tax return position has a realistic possibility of success if challenged by the IRS

answer; i believe its (d) intrinsic;