Answer:
The correct answer is A) inconsistent reasoning; saving $20 is saving $20.
Explanation:
Tony is making an uninformed decision or more strictly, his reasoning is inconsistent. A flat discount of $20 is applicable to all products. Whether he buys something that is worth $50 or $500, his savings would still be the same.
All other options are wrong. If e.g. he this was a flat 20% discount, his savings would have been much different. e.g. 20% of $50 is $10 while it equals to a $100 for a $500 product.
At this point, he would have to make rational decision on what he really needs to buy.