Final answer:
Memorandums are typically used to communicate with persons who work in one's office.
Step-by-step explanation:
A memorandum, commonly known as a memo, is a type of business document that is typically used to communicate with persons who work in one's office or organization. This means that option 1 - who work in one's office - is the correct answer. Memorandums are internal documents that are used to convey important information, instructions, or announcements within a company or organization.