Income may be recognized from cancellation of debt in which instance?

My group and I disagree on the following ones:Income may be recognized from cancellation of debt in which instance?The debt cancelled was intended as a giftthe debt was cancelled by a purchase price reductionThe debt would have been deductible by the taxpayer if paidDebt cancelled was from the mortgage on a taxpayer’s second homeBoot isNot a factor in determining basis of property received in an exchangeCash paid or received in an exchangeUnlike property received in an exchangeUnlike property paid in an exchangeWhich taxpayer is not able to deduct NOLs incurred by its entity?A shareholder in a C corporationA partner in a partnershipA partner in an LLCA sole proprietorOne of the following is not a benefit of Rev Rul 2009-9.The loss may be reported for the year of discovery or on previous year returnThe loss is an ordinary theft loss, not a capital lossThe loss is reported on Form 4684The loss is considered an investment loss not subject to the per-event floor or the 10%-of-AGI threshold.