Answer:
The sentence which contains one of the errors mentioned in the checklist is:
B. Rainbows occur when the sun shines thru a rain shower.
Step-by-step explanation:
Even though we have grown used to seeing the word "thru" around, it is actually a misspelling. The correct spelling is "through", while "thru" is a way to write the word that focuses on how it sounds. We can often see the latter in text messages, or even in "drive-thru" signs. With that in mind, we can say option B contains the error mentioned in number 4 of the checklist.