This exercise is found on the Internet. I wonder why only one of the answers is given as the standard one. Maybe it has something to do with regionalism. I often feel confused when there are multiple choices. What should students do when they take an exam where there are more than one answer?
Not so much regionalism as presciptivism, Chariot. Many language proficiency tests, especially foreign-conceived ones, are based on a grammar that is outdated and overly restrictive; their vocabularies are based on bilingual dictionaries written in the 1940s or 50s. They do not reflect the (especially, spoken) language as it exists in all its major dialects, and it oversimplifies the varieties o