Presented below are a number of operational guidelines and practices that have developed over time. Select the assumption, principle, or constraint that most appropriately justifies these procedures and practices. (Do not use qualitative characteristics.) (a) Intangible assets are capitalized and amortized over periods benefited. select an option (b) Brokerage firms use fair value for purposes of valuing investments. select an option (c) Each enterprise is kept as a unit distinct from its owner or owners. select an option (d) All significant post-balance-sheet events are reported. select an option (e) Fair value changes of fixed assets are not recognized in the accounting records. select an option (f) Supplemental information is presented so that investors will not be misled. select an option (g) Revenue is recorded at point of sale. select an option (h) All important aspects of bond indentures are presented in financial statements. select an option (i) Rationale for accrual accounting. select an option (j) The use of consolidated statements is justified. select an option (k) Reporting must be done at defined time intervals. select an option (l) An allowance for doubtful accounts is established. select an option (m) Goodwill is recorded only at time of purchase. select an option (n) A company charges its sales commission costs to expense.