The correct answer is Solve the problem​. Key Points Let's look at the meaning of the given idiom: Cross that bridge when one comes to it​- deal with a problem when and if it arises Example: I don't know how we'll pay the bills if you quit your job, but we'll cross that bridge when we come to it. ​Thus from the explanation given above, we find that the 4th option is the correct choice. ​​​​Additional Information Let's look at the origin of the idiom: Don't cross the bridge until you come to it is an English language idiom cliché. Though the history of where the phrase came from is unclear, it is believed to have originated from a proverb by Henry Wadsworth Longfellow.