If 1 + i 1 - i m = 1 , then m can not be equal to

Given that, ${\left(\frac{1+i}{1-i}\right)}^m=1$

Here, 

$\frac{1+i}{1-i}=\frac{1+i}{1-i}\times \frac{1+i}{1+i}$

$=\frac{{\left(1+i\right)}^2}{2}$

$=\frac{1+i^2+2i}{2}$

$=\frac{2i}{2}$

$=i$

Now, we get ${\left(\frac{1+i}{1-i}\right)}^m=i^m=1$

We know that, $i^4=1$

From options we see that only $1934$ doesnot satisfy this condition.