Select the most appropriate idiomatic expression to fill

Solution

The idiom "get down to brass tacks" means to focus on the essential details of a matter. Since the sentence talks about finalizing the budget before starting the project, this idiom is the most appropriate choice."Beat around the bush" means avoiding the main topic, which does not fit the sentence."Cut corners" means doing something cheaply or carelessly, which is not relevant here."Throw in the towel" means giving up, which does not match the context.Thus, option 2 "get down to brass tacks" is the correct answer.