The crucial reason for determining whether an item is deductible as an expense under 162 or under 212 is that

a. production-of-income expenses are not deductible.

b. 162 business expenses usually are deductions for A.G.I., while 212 production-of-income expenses usually are miscellaneous itemized deductions.

c. 162 business expenses are deductions from A.G.I., while 212 production-of-income expenses are deductions for A.G.I.

d. it resolves certain ownership questions.