Which equation has 1 solution?

IwI = - 2

IwI = - 1

IwI = 0

IwI = - 1

Absolute value is alwas positive

so all of them excet the 3rd one are false

|w|=0 has 1 solution

if the last one was |w|=1 then ther would be 2 solutions, - 1 and 1

answer is |w|=0