Final answer:
Contacting an existing customer who is vacationing in another state by a BD Firm with no physical presence in that state is an example of interstate commerce, as the business activity crosses state borders. The correct option is b.
Step-by-step explanation:
A BD (Broker-Dealer) Firm with no office in a state contacting an existing customer vacationing in that state is an example of interstate commerce. Interstate commerce refers to any work, business, or transactions that cross state lines or otherwise involve more than one state. In this context, the firm is engaging in business activity with a client who is currently out of the client's home state, resulting in the transaction being across state lines.
This scenario does not signify a legal issue, assuming the firm has the proper federal registrations to conduct business across state lines and there are no state-specific regulations being violated.
Similarly, it does not imply a violation of jurisdictional boundaries, as firms typically have to comply with federal laws that govern interstate commerce rather than just state laws. Last, it is not necessarily a customer privacy infringement unless the firm is misusing the customer's information without consent.
Hence, Option b is correct.