Athird-level heading of a memo is typically a. typed in all capital letters. b. never followed by text. c. placed at the left margin of the memo. d. a subheading of the fourth-level heading.

The answer to this question is the letter C which is the "placed at the left margin of the memo". This is the answer and this is found as the third level heading which contains the CC or the courtesy copy. The person who is also allowed to receive the copy of the memo. 

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