Which one of the following is NOT a valid identify? Option ‘a’ is
| Which one of the following is NOT a valid identify?
A.
B. 
C. 
D. 
Please scroll down to see the correct answer and solution guide.
Right Answer is: D
SOLUTION
Option ‘a’ is correct
Option ‘b’ is correct
If xy = 0 then 
Hence option ‘c’ is correct
Option ‘d’ is NOT correct, because
is not equals to
