Answer:
 Incremental profit = $30000
so correct option is a. $30,000 
Step-by-step explanation:
given data
Variable costs = $75 
Fixed costs = 30 
sales price = $165
to find out 
incremental profit or loss from accepting
solution
we get here contribution per unit will be here as 
contribution per unit = $165 - $75 
contribution per unit = $90 
now we get here loss on contribution for giving up regular sale that is 
loss on contribution = $3000 × $90 
loss on contribution = $270000 
and 
now we get Incremental contribution for special order will be 
Incremental contribution = (135 - 75) × 5000 
Incremental contribution = $300000 
and 
 Incremental profit will be = $300000 - $270000 
 Incremental profit = $30000
so correct option is a. $30,000