Spam filters can vary in logic, but most spam filters use:

Spam filters primarily rely on content- or keyword-based logic to assess and categorize incoming emails. This method analyzes the text within the email for specific keywords, phrases, or patterns that are commonly associated with spam. By filtering messages based on their content, spam filters can effectively identify and block unwanted or potentially harmful emails, helping to maintain a cleaner inbox for users.

In practice, this form of analysis can involve looking for certain words or phrases, analyzing formatting, and checking for patterns typical of spam communications, all of which contribute to the categorization of emails as either legitimate or spam.

The other options presented do not align with conventional spam filtering methods. Employing people to review emails would be impractical at scale and inefficient compared to automated filters. Meanwhile, references to highly processed meat products and random number generators have no relevance within the context of email filtering techniques, making them unsuitable choices.