Answer:
B. constructive delivery
Explanation:
Based on the information provided within the question it can be said that Presenting the key is constructive delivery. This term refers to transferring a title by operation of law when the actual transfer is impossible. Such as is the case in this scenario, since the shares of Tesla stock are locked in a safety deposit box and are out of reach, Rikki cannot hand them the shares. Instead he hands them the key which they can then use to retrieve the shares.