Final answer:
To find the gross sales generated by selling the designer shirts, calculate the revenue from selling the shirts at different prices and subtract the amount of returned shirts.
Step-by-step explanation:
To find the gross sales generated by selling the designer shirts, we need to calculate the total revenue from selling the shirts at different prices.
First, calculate the revenue from selling 100 shirts at a discount. The discounted price is $33.75, so the revenue from selling these shirts is 100 * $33.75 = $3375.
Next, calculate the revenue from selling the remaining 200 shirts at the original price of $45. The revenue from selling these shirts is 200 * $45 = $9000.
To find the total gross sales, subtract the amount of returned shirts from the total revenue: $3375 + $9000 - $45 = $12,750.
Therefore, the correct answer is D) $12,750.