[单选题]
The diagram shows a beam of light passing from medium $X$ to medium $Y$.
If the angle of incidence of the light increases, which of the following changes can be implemented to keep the angle of refraction the same?
I. Medium X can be replaced with another medium which has a lower refractive index.
II. Medium X can be replaced with another medium which has a higher refractive index.
III. Medium Y can be replaced with another medium which has a higher refractive index.
A. Only $I$
B. $I$ and $III$ only
C. $II$ and $III$ only
D. $I$, $II$, and $III$
