D. (12) It was started in 2009 by actor Matt Damon and Gary White, the co-founder of Water partners.
Explanation:
The last sentence contains the word 'partners" which should be capitalized and written as "Partners" instead. The reason is that is is a proper noun. A name of a company which should be written with a capital letter.
All the other options in the question are written correctly except this sentence number twelve.
Therefore the correct option is D. (12) It was started in 2009 by actor Matt Damon and Gary White, the co-founder of Water partners.
