D. Most credit cards allow cash advances at an automated teller machine (ATM).
When using acronyms in writing it is always important to clarify what the acronym stands for. To do this, when the acronym is first used, the writer must tell the reader what it stands for. Instead having a full sentence to say "ATM stands for automated teller machine", the writer can put acronym in parentheses after the name. Then the writer can use the acronym throughout the rest of the writing.