Answer:
b. Memos are commonly written to people within your own organization.
Step-by-step explanation:
Memos are the moderately formal means of communication that is used within the same organisation. It is also a formal document that is used within the same organization.
Memos are formal but not highly formal. They are used as a form of relaying short messages, usually a page or so. This is done with the logo of the organization of the company, using the company's template. But even though they are more efficient and flexible than normal letter writing, they still cost a lot and takes delivery time.