College accounting questions?

This is for a pre-test on several chapters coming up during next teachings in class. I'm having a difficult time finding answers to some questions, in my book:
~When does the warranty cost appear on the statement of cash flows?
a- when there is a settlement of a warranty claim made by a customer
b- when the warranty obligation is recognized
c- when the sale of merchandise is made
d- none of the above.
I think it is C.
~What does the accts receivable turnover ratio measure?
a- average balance of accts receivables
b- how quickly does the accts receivables increase
c- how quickly accts receivables turn into cash
d- how quickly inventory turns into accts receivables
I think its C.
~When is it acceptable to use the direct write-off method of acct'ing bad debts?
a- if the business applying the entity concept
b- if the business is NOT using GAAP
I think it is B.
Please help! Thanks

~When does the warranty cost appear on the statement of cash flows?
a- when there is a settlement of a warranty claim made by a customer (i.e. when there is an actual cash outflow)

~What does the accts receivable turnover ratio measure?
c- how quickly accts receivables turn into cash

~When is it acceptable to use the direct write-off method of acct'ing bad debts?
b- if the business is NOT using GAAP
The Internal Revenue Service permits companies to take a tax deduction for bad debts only after specific uncollectible accounts have been identified. Unless a company's uncollectible accounts represent an insignificant percentage of their sales, however, they may not use the direct write-off method for financial reporting purposes. Since several months may pass between the time that a sale occurs and the time that a company realizes that a customer's account is uncollectible, the matching principle, which requires that revenues and related expenses be matched in the same accounting period, would often be violated if the direct write-off method were used. Therefore, most companies use the direct write-off method on their tax returns but use the allowance method on financial statements.