Using the Code index, identify the key Code section(s) addressing the following:
a. Corporation's ability to deduct mining and exploration costs.
b. Taxation of Social Security benefits of nonresident aliens.
c. Definition of Head of Household.
d. Valuation of a gift.
e. Sick pay benefits of employees.
f. Deductibility of face lift.
g. Bad debt reserves.
h. Statute of limitations for filing an amended return.
i. Withholding requirements for tip income,
j. Penalties for tax fraud.