Study the following Information to answer the given questions: In a certain code ‘a friend of mine’ is written as ‘4 9 1 6’, ‘mine lots of metal’ is written as ‘3 1 0 9’ and ‘a piece of metal’ is written as ‘7 1 6 3'. What is the code for 'piece?
1)3
2)6
3)1
4)7
5)Cannot be determined

Explanation

4