You have to mark the 3rd box (contesting the infraction). Then at the hearing, you ask the judge to grant a deferred finding. It is at the judge’s discretion to grant that finding.
The good thing is that if you were to get a ticket for this violation, it would be considered a non-moving violation. This means that it will not have an effect on your driver’s license and you don’t need to hire an attorney. You can go to court and mitigate the charge, i.e. lower the fine amount.
I would strongly recommend hiring a local attorney for both tickets. If your son is found to have committed both of the infractions, most likely his insurance is be substantially increases. Most attorneys that handle traffic infractions on a regular basis a very high success rate of dismissing the infraction or keeping the infraction of the record. You will save a lot of money in the long run.