Choose the sentence that is closest in meaning to each of the following questions.Câu hỏi Maria started to work as a volunteer at an animal shelter four years ago. A. It’s four years since Maria works as a volunteer at an animal shelter. B. Maria has been a volunteer at an animal shelter for four years. C. Maria is working as a volunteer at an animal shelter in the last four years. D. This is the fourth year Maria was a volunteer at an animal shelter.