Which of the following is an effective method to prevent shoplifting?

Greet customers upon entry is an effective method to prevent shoplifting because it establishes a connection between staff and customers right from the start. This action serves multiple purposes: it makes customers feel noticed and welcomed, which can deter potential shoplifters who might not want to be scrutinized, as they are more likely to feel observed. Additionally, greeting customers creates a positive shopping atmosphere and may encourage legitimate purchasing behaviors.

While other options may contribute to loss prevention strategies, greeting customers emphasizes the human element of customer service that can be highly influential in reducing theft. Keeping expensive items locked up, installing hidden cameras, and using mirrors are effective tactics as well, but they tend to focus more on surveillance and control rather than engagement and interaction. Engaging with customers helps foster a sense of accountability and can often be the first line of defense against shoplifting.