The temporary permit mailed to a salesman shall expire...

The correct answer indicates that a temporary permit mailed to a salesman expires at the end of 120 days. This timeframe is established to provide salespersons a limited window during which they can engage in their activities while their permanent licensing is processed. The 120-day period strikes a balance, allowing enough time for applicants to fulfill any necessary requirements while also maintaining regulatory oversight.

The duration of 120 days is a common standard across various jurisdictions for temporary permits in many fields, ensuring that new salespeople are not left without the ability to operate while they wait for their official credentials. This approach helps maintain a flow of commerce by allowing new entrants into the field without extensive delay while ensuring that they are still subject to eventual approval and oversight once their permanent license is issued.

Some of the other choices suggest different durations, such as 90 days or conditions regarding extensions, which do not align with the standard framework governing temporary permits in this context. Therefore, this emphasis on a 120-day expiration period signals commitment to thorough review processes while allowing for a reasonable grace period for individuals to start their sales careers.