The correct answer is B. find a specific person to address in the letter
I assure you the answer is correct, as i have just completed the corresponding quiz.
Some people on earth, don't get enough water everyday and they have to walk 5km at least to get a bucket of filthy water. So people who have clean water everyday sometimes waste it and pour it into a drain. However, they do not think about the people who actually need it and they take it for granted.