Yahoo provides three methods to recover the account: a mobile phone, an alternative email, and security questions. In order to recover it, I suggest you try others options. Open the official web page, check the first box, click Next, and follow the on-screen instructions. If your account is not configured with any of these alternative recovery methods, I recommend contacting Yahoo Customer Care.
Note: In order to find the answer for the security question, you can ask your wife/husband.