The best way to accomplish this scenario is to select General Address for the Custom Reply-To Address when sending the list email. This option allows the marketer to specify any email address as the reply-to address, regardless of the sender or the prospect owner. In this case, the marketer can enter bdr@lenoxsoft.com as the reply-to address, so that any prospect replies will be directed to the business development reps. Option A is not correct because selecting Specific User for the Sender will not allow the marketer to send the email on behalf of the assigned sales users, but only from a specific Marketing Cloud Account Engagement user. Option B is not correct because selecting General User for the Sender will not allow the marketer to send the email on behalf of the assigned sales users, but only from a general address that is not associated with any Marketing Cloud Account Engagement user. Option C is not correct because selecting Assigned User for the Custom Reply-To Address will not allow the marketer to direct the prospect replies to bdr@lenoxsoft.com, but only to the user who owns the prospect record. References: Email Sender Options: Leverage CRM User Lookup in MCAE (Marketing Cloud Account Engagement), How to Send an Email in Marketing Cloud Account Engagement: A Recipe | The DRIP - Salesforce Ben, Sender and Reply-To Options - Salesforce