Betty hires Sam, a CPA, to prepare her current federal income tax return for the first time. In preparing the return, Sam finds a material error in last year's return. Sam should:

I.	do nothing and see if the IRS catches the error.
II.	inform Betty and recommend corrective measures.
III.	immediately contact the IRS.
IV.	immediately call Betty and tell her he cannot complete this year's return.

	a.	Only I is correct.
	b.	Only II is correct.
	c.	Only III is correct.
	d.	I and III are correct.
	e.	I and IV are correct.