Final answer:
ABC Bank is required to follow up with the consumer to verify the validity of a change of address request due to the possibility of fraudulent activities.
Step-by-step explanation:
In order to verify the validity of a change of address request received from a consumer, ABC Bank is required to follow up with the consumer. The primary reason for this is the need to prevent fraudulent activities. Sudden or unusual changes in banking practices, such as a change of address, inclusion of additional names on bank cards, or abrupt changes to a will, can raise suspicions of potential fraud.