Question 55 of 75. In 2021, Martha's business use of her vehicle (placed into service on April 1, 2019) fell to less than 30%. In prior years, she used the vehicle more than 50% for business, and she had been using the modified accelerated cost recovery system (MACRS) to recover the cost basis of this asset. What method, convention, and recovery period must she use in 2021? 150% declining balance (DB), mid-month convention, alternative depreciation system (ADS) recovery period. O 200% declining balance (DB), half-year convention, general depreciation system (GDS) recovery period. Straight-line method (SL), mid-month, alternative depreciation system (ADS) recovery period. Straight-line method (SL), half-year convention, alternative depreciation system (ADS) recovery period.