Answer: D. Elaborative Rehearsal
Explanation: Elaborative rehearsal an efficient method of storing information in memory. Elaborative Rehearsal attempts to find a very effective and technical way of storing information in long-term memory. It involves a technique of associating or connecting a new information with an already stored information in an individual's long-term memory.
In the scenario above, Bob attempts to make a connection between is telephone number and the gadget being sold 'LAMP' which is already a commonly known name. This aids the storage of the phone number along with the already known information in his customer's long-term memory.