if its a report, you should probably go with formal opposed to informal, and humorous doesn't seem good for a school report. And it's history, not science so not scientific.
It should be c) formal because it shouldn’t be humorous or no ones going to take the person writing seriously , it shouldn’t be informal because that’s not correct for a report , and it shouldn’t be scientific because this is for social studies not science :) hope this helped
Your teacher has asked you to write an article for the school magazine providing solutions on how to save water in your city/town/village. write your article (100-120 words).
