The National Data Base Opt Out Register is used to:

• A. allow unsolicited calls.
• B. prevent unsolicited calls to listed numbers.
• C. register customers for marketing.
• D. not have any effect.

Answer: (B)

The idea behind the National Data Base Opt Out Register is to give individuals a shield against direct marketing calls. By adding a number to the opt-out list, you instruct marketers that you do not want to receive unsolicited marketing communications, so organisations must not use that number to contact you for marketing purposes and should remove it from their marketing lists. This helps protect privacy and ensures compliance with telemarketing rules. The other options don’t fit because this register is not used to allow calls, not about registering people for marketing, and it does have an effect by reducing unsolicited contact.