You will be staying abroad during your license renewal period and cannot renew (including any regular aptitude test) in time. Which statement is correct?

1. ①A stay abroad is not a reason for postponement, so the license is revoked as soon as the renewal period passes.
2. ②You may renew early before the renewal period, or apply for a postponement with supporting documents.
3. ③A postponement of up to 10 years may be granted.
4. ④A person granted postponement only needs to renew within 1 year after returning to Korea.