Answer and Explanation:
The computation is shown below;
For Alternative A
Cost to buy new machine -$119,000.00
Cash received $55,000.00
Reduction in variable manufacturing cost ($33400 - $23000) ×5 $52,000.00
Total change in net income -$12,000.00
For Alternative B
Cost to buy new machine -$112,000.00
Cash received $55,000.00
Reduction in variable manufacturing cost ($33400 - $10200) × 5 $116,000.00
Total change in net income $59,000.00
So here Xinhong should purchase a machine that belong from Alternative B.