Final answer:
Deductions that reduce both regular taxable income and AMTI are charitable contributions, casualty losses in Presidentially declared disaster areas, and home mortgage interest.
Step-by-step explanation:
The deductions that reduce both regular taxable income and Alternative Minimum Taxable Income (AMTI) include: a) Charitable contributions, c) Casualty losses (in a Presidentially declared disaster area), and d) Home mortgage interest. Gambling losses, which are referenced in option b), do not reduce AGI but can only be claimed to the extent of gambling winnings for both regular tax purposes and AMT. Therefore, the correct choice is e) all of the above as each of these deductions can reduce both regular taxable income and AMTI.