Answer:
c. increase of $7,875
Step-by-step explanation:
The computation of the change in operating income is shown below:
= Number of pens for one-time order × (Selling cost per unit - variable cost per unit)
= 3,500 pens × ($3 per unit - $0.75)
= 3,500 pens × $2.25 per unit
= $7,875
The (Selling cost per unit - variable cost per unit) is also called contribution margin per unit
All other information which is given is not relevant. Hence, ignored it