cfa經濟問題 - 金融分析師

請問一下大家,
看了很久 ,還是不甚理解,

For a particular product produced by a firm,the quantity at which demand

is unit elastic is most likely the quantity that maximizes:

A.total profit from the product but not total revenue from the product.

B.total revenue from the product but not total profit from the product.

C.both total profit from the product and total revenue from the product.

希望可以告知這題目考的觀念為何?

謝謝!

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