Answer:
Step-by-step explanation:
If someone wrote a paper and that sentence was included, I'd overlook it if I was making the paper.
If you want to be 100% correct, you could say The ray of sunlight passed through the raindrop (singular). I think that's too nit picky but it is correct.
Sunlight is singular. Raindrops should be as well, but it sounds awkward. See my correction above.