Which option reflects an informal communication method?

An informal communication method is characterized by a relaxed tone, casual language, and a lack of adherence to formal structure. A text message to a colleague exemplifies this informal approach, as it often includes conversational language, abbreviations, and may not follow the strict protocols or formatting seen in more formal methods of communication.

In contrast, an email to a superior typically involves a more formal structure and tone since it is directed towards someone with authority. Official memos and business letters are formal types of correspondence that adhere to established formats and protocols, intended for clear and professional communication. The informal nature of a text message allows for quicker, more spontaneous interactions, making it suitable for casual exchanges among peers, which aligns with the qualities of informal communication.