The x-axis is the real axis, and the y-axis is the positive imaginary (i) axis.
So the number w is approximately -1+3i.
Two ways to solve the problem.
1.
-i w = -i (-1+3i) = -i (-1)+ (-i)(3i) = +i +3, so the answer is the point A.
2.
You can consider multiplying by i is a counter-clockwise rotation of 90 degrees, and -i is a -90 degrees (i.e. clockwise). So we can rotate w by -90 degrees to get point A.