When is an original work considered public domain? a. when posted via social media. b. when is it posted on the internet c. when a copyright symbol is not included with the piece of work d. when explicit permission is given by the author/owner

Any materials not protected by copyright, patent laws or trademark are referred to as copyright. Generally, the public owns these works, and anyone is allowed to use public domain works without obtaining permission. There are various common ways that these works may end up arriving in the public domain. One of those ways includes the expiration of copyright. The copyright owner may also fail to follow renewal rules that govern copyright. The copyright owner may as well decide to place his or her works deliberately in the public domain.