Answer:
1. Grace was credited for three months taxes.
Step-by-step explanation:
We need to understand proration. The buyer needs to pay for the taxes the date the property is owed to him, and the seller needs to pay for the taxes till he is having the property. Now he has paid for a year, and the year ends on October 1st. However, he is going to owe the property until Jan 1st. And hence, Grace is credited with the 3 months taxes.