A. The price variance is calculated as follows: (Actual Price - Standard Price) × Actual Quantity. The purchase price variance is calculated using all of the units purchased, not just the units that are put into production. The purchase price variance is $135 unfavorable [($0.75 - $0.72) × 4,500]. The actual price exceeds the standard, thus, the variance is unfavorable.

B. The price variance is calculated as follows: (Actual Price - Standard Price) × Actual Quantity. The purchase price variance is calculated using all of the units purchased, not just the units that are put into production. See the correct answer for a complete explanation.

C. The price variance is calculated as follows: (Actual Price - Standard Price) × Actual Quantity. The purchase price variance is calculated using all of the units purchased, not just the units that are put into production. See the correct answer for a complete explanation.

D. The price variance is calculated as follows: (Actual Price - Standard Price) × Actual Quantity.  The purchase price variance is calculated using all of the units purchased (4,500), not just the units that are put into production (4,100). See the correct answer for a complete explanation.