Readers who are not the primary addressee, but are still included as reviewers are called:

The question asks to identify the term for readers who are not the primary addressee but are included as reviewers. The primary audience* is the direct recipient of the message, the person or group for whom the message is specifically written. The secondary audience* consists of people who are not the primary addressee but will still read, be affected by, or need to act on the message. This often includes reviewers, advisors, or those who implement decisions. The tertiary audience* includes people who may encounter the message much later or indirectly, often for general information or historical reference. Given that these readers are not the primary addressee but are included as reviewers, they fit the definition of a secondary audience. The correct option is: C. Secondary audience