Answer:
The correct answer is (A) the output effect is stronger than the price effect
Explanation
The price elasticity determines which effect is stronger. Â
In this case, Â
Marvin reduces his price from $25 to $20, the quantity sold increase and total revenue increase by $40.
As the revenue increase when price goes down, Â we can say we have a elastic demand. Â Also, if we have an increase of revenue, Â that means that the output effect is stronger than the price effect