Which of the following constitutes an act of 'breaking' as described in property crimes?

The act of 'breaking' in the context of property crimes generally refers to any form of physical intrusion or entry that is not authorized, even if it may seem minimal. Pushing open a door slightly, depending on the circumstances, signifies an effort to enter without full permission, which can be construed as a form of breaking. This contrasts with the other options, as they either entail a higher degree of force (like breaking a window), involve accessing a hidden key without permission (which implies dishonesty but not physical breaking), or using a key which indicates authorized entry. In property crimes discourse, even minimal physical actions can be categorized under 'breaking' if they indicate the intent to enter unlawfully. Therefore, the subtle physical act of slightly pushing a door open can indeed fall under this classification.