Which of the following constitutes breaking or entering?

The correct choice, which defines breaking or entering, refers to the act of gaining entry into a structure without permission. This concept is crucial in criminal law and pertains to trespassing and burglary. The essence of breaking or entering lies in the unauthorized intrusion into someone else's property, which serves as a legal foundation for many property crime charges.

In contrast to this correct answer, simply walking past a building does not involve entering the property and thus does not meet the criteria for breaking or entering. Entering through a door with consent signifies that permission has been granted, negating the act of breaking or entering. Using a key to enter a friend's home also indicates that permission has been given, either explicitly or implicitly, making it a lawful entry rather than a breach of property rights. Therefore, it is essential to understand that the crux of breaking or entering involves the lack of consent from the property owner, which is accurately captured by the correct answer.