The 90 day certificate issued to an applicant for an original salesperson's license...

The 90-day certificate issued to an applicant for an original salesperson's license is a temporary credential that allows individuals to operate under specific conditions while they prepare for their licensing exam. This type of permit is generally designed for a short duration, usually allowing the individual to gain experience and engage in preliminary sales activities.

Option C states that this certificate may not be renewed, which is accurate because temporary certificates like these are typically intended to encourage prompt completion of necessary licensing requirements, including passing the salesperson's exam. As such, the expiration of the certificate compels applicants to complete the test and obtain a full license.

The other choices suggest various renewal options or conditions that would allow an extension of the certificate's validity. However, the nature of a 90-day temporary certificate is fundamentally about urgency and completion of the licensing process rather than providing an avenue for renewal. Therefore, recognizing that a renewal is not permissible aligns with the purpose of the certificate to motivate applicants towards timely licensure.