The Correct option will be : -
A. it changes its direction as it passes into a new medium.
because, light travels with different speeds in different mediums, and this occurs due to difference in optical density of different mediums.
And bending of light depends upon the change in medium,
for example :
- when travelling from optically denser medium to optically rarer medium it bends away from normal.
- when travelling from optically rarer medium to optically denser medium it bends towards the normal.
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