July2016 cs Q20

0. Consider the following database table having A, B, C and D as its four attributes and four possible candidate keys (I, II, III and IV) for this table : I : {B} II : {B, C} III : {A, D} IV : {C, D} If different symbols stand for different values in the table (e.g., d1 is definitely not equal to d2), then which of the above could not be the candidate key for the database table ?
A B C D
a₁ b₁ c₁ d₁
a₂ b₃ c₃ d₁
a₁ b₁ c₁ d₂

Answer
Comment
Array

Option : C
Explanation :

Forgot your password?

I agree with the Terms.