Answer:
fringes move farther
Step-by-step explanation:
The relation between the distance between the fringes is given by
y = Dλ/d
where, D is the distance between the plane of slit and the screen
d is the width of slit, λ is the wavelength of light used.
As the slit made narrower, that means d decreases, the value of y increases, that means the fringes move farther.