I recently did this topic in science class - the answer is A ;)
Answer:out of nowhere like what are you asking
Explanation: :D
Answer: perpendicular to it oscillations.
Explanation: A transverse wave is a wave whose oscillations is perpendicular to the direction of the wave.
By perpendicular, we mean that the wave is oscillating on the vertical axis (y) of a Cartesian plane and the vibration is along the horizontal axis (x) of the plane.
Examples of transverse waves includes wave in a string, water wave and light.
Let us take a wave in a string for example, you tie one end of a string to a fixed point and the other end is free with you holding it.
If you move the rope vertically ( that's up and down) you will notice a kind of wave traveling away from you ( horizontally) to the fixed point.
Since the oscillations is perpendicular to the direction of wave, it is a transverse wave
Answer
The refracted wave must obey Snell's equation
Ni sin θi = Nr sin θr
If Nr differs from Ni then sin θr will differ from sin θi
If the wave originates from point A and ends at point B then Snell's Law shows that the time for light to get from point A to point B is a minimum.