Question

_____ is a unique key
1) three
2) four
3) five
4)six​

Answer 1

five is correct ans

hope it helps

Answer 2

Answer:

Unique key is a constraint that is used to uniquely identify a tuple in a table. Multiple unique keys can present in a table. NULL values are allowed in case of a unique key. These can also be used as foreign keys for another table

Hope this helps you☺