Who will get Xtra Piece

Four friends in the sixth grade were sharing a pizza.They decided that the oldest friend would get the extra piece. Radha is two months older than Ganesh, who is three months younger than Nidhi. Karthik is one month older than Ganesh. Who should get the extra piece of pizza?

a. Radha
b. Ganesh
c. Nidhi
d. Kathik

Watch this space for answer in a week.