Which of the following set is not a null set ?

Options

A. `P = {x//x in N, 2x +1` is even}
B. `Q= {x//x in I, x ^(2)` is not positive}
C. `R= {x//x in N, x ` is odd and `x ^(2)` is even}
D. `S= {x//x in R, x ^(2) +1=0}`

Answer

B