# What is the smallest positive integer n , for which $\; (1+i)^{2n} = (1-i)^{2n}$

$(a)\;1\qquad(b)\;0\qquad(c)\;2\qquad(d)\;4$

Explanation :
n=2 , because $\; (1+i)^{2n} = (1-i)^{2n}$
$(\large\frac{1+i}{1-i})^{2n} =1$
$(i)^{2n} =1\;$ which is possible if n=2 $\quad [i^{4} =1]$