The Robinson$-$Patman Act makes it illegal for a business entity to discriminate in price under some circumstances. Which of the following scenarios involves a potential violation of this act?

Multiple Choice

Shifty Incorporated made three different sales to Friendly Corporation, holding out for a higher price on the third and final sale, which represented a $25$ percent increase on the price offered for the first two sales.

Advantage Technologies quoted a price of $$1$ million to Company ABC and $$2$ million to Company XYZ for the exact same product.

Aggressive Manufacturing sold their new product to Company A for $$100,000,$ then refused to sell the same product to Company $B$ for less than $$150,000,$ and as a result no deal was made.

Shilco Incorporated sold the same software system for $$200,000$ to DEF Corporation and $$250,000$ to EFG Corporation.