A concave mirror for face viewing has focal length of 0.4m. The distance at which you hold the mirror from your face in order to see your image upright with a magnification of 5 is:

Correct option is D.
0.32m
m = f/(f-u)
5 = -0.4/(0.4 - u)
5(0.4 - u) = -0.4
2 - 5u = -0.4
2 + 0.4 = 5u
2.4 = 5u
u = 2.4/5 = 0.48m
The distance at which you hold the mirror from your face in order to see your image upright with a magnification of 5 is 0.48m. However, this answer is not present in the options. Let's re-examine the magnification formula.
For a concave mirror, magnification m is given by:
m = -v/u = f/(f-u)
Where:
m = magnification
v = image distance
u = object distance
f = focal length
Given m = 5 (upright and magnified image), f = 0.4m
5 = -v/u
5 = 0.4/(0.4 - u)
5(0.4 - u) = 0.4
2 - 5u = 0.4
5u = 2 - 0.4 = 1.6
u = 1.6/5 = 0.32 m
Therefore, the correct option is 0.32m