Megan prepared for compensation a Federal income tax return for Joan. Joan’s return included an aggressive interpretation of the rules concerning overnight business travel. Megan is not liable for a preparer penalty for taking an unreasonable tax return position if:

a. The IRS found that the travel deduction was frivolous, but Joan disclosed the position in an attachment to the return.
b. There was substantial authority for Joan’s interpretation of the travel deduction rules.
c. There was a reasonable basis for Joan’s interpretation of the travel deduction rules.
d. The tax reduction attributable to the disputed deduction did not exceed $5,000.