Answer:
A) horizontal lines
Explanation:
An indifference curve is a curve that shows the two combinations of goods that gives a consumer equal satisfaction.
If Monroe's utility doesn't increase with the consumption of crab cakes, his indifference curve would be a horizontal line. This is because crab cakes and tuna are perfect subsistuites. Monroe would be willing to substitute tuna for crab cakes as he doesn't derive any satisfaction from consuming tuna.
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