Acces to standard options (unit) from the query

Hi guys, i’d like to know if there is a way to access to standard options from the query, im asking this because i’d like to give users a variable where they can choose what currency they want to see the values but this gives me a problem for example, if i change from $ to € the values will change because i put that fuction in the query but the unit doesn’t change, so how can i to change the unit from the query? is that possible?