Answer: B) Oversubscription privilege
Explanation:
Oversubscription privilege is a provision that is given to the shareholders of a company during the issuance offers of rights or warrants that allows them to buy any outstanding shares remaining if other shareholders have had a chance to buy them and did not.
Isabelle can therefore purchase these unsubscribed shares from the six shareholders who have opted not to participate in the rights offering under the Oversubcription clause.