Answer:
D) Susie would buy more massages and fewer rounds of golf,as predicted by the substitution effect.
Step-by-step explanation:
Let's check the utility that Susie gets from consuming these products.
The second round of golf gives her 20 units of satisfaction at $20 = 20/20 = 1
The third massage gives her 30 units of satisfaction at $30 = 30/30 = 1
But now the price the price for massage has come down to $15. The ratio of their prices would be
20/15 = 1.333
1.3 is greater than 1
So she should substitute golf for massages