Answer: The answer is D increase by $6,975
Explanation:
 Income statement
 $
Revenue (16,000 × 10.25) 164,000
Direct Material 164,000
Direct Labour. 100,000
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Prime Cost 264,000 
Overhead 
Variable overhead 20,000
Selling &Administrative(fixed) 32,500
 ----------
 52,500
Total Cost.  316,500 
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Operating income. (152,500)
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Allocation of overhead cost on the basis of direct labour
 $
Direct Labour. 100,000
Variable overhead( 0.2 × 20,000) 4,000
 -----------
Total overhead. 104,000
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Direct Labour = Total overhead / Total production 
= 104,000/16,000
= 6.5
These variable cost is a relevant cost, we can now compare the estimated relevant cost with the relevant revenue if the order is accepted 
 $ 
Additional Revenue (4,500 × 8.05) 36,225
Less: unit purchased (4,500 × 6.5) 29,250
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Excess of revenue over cost. 6,975
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Therefore the profit will be increased by $6,975