Help me understand how giving a child the choice between a Pepsi and a Mountain Dew is a good thing? And at 10:30am to boot??

We aren’t talking about a teen child. This is a five year old.

We were at a bagel shop yesterday when a mom came in with her daughter. They had been in the karate class next door.
After receiving her new belt this was supposed to be a reward. Poison as a reward ? I’m confused.
Mom gets a half point for mentioning that there is caffeine in them both but a -1000 for giving the final decision to her five year old.

I understand a lot of people don’t get the whole Corn syrup, GMO thing but no caffeine for kids is pretty old school education, isn’t it ?

What about actually being a parent and setting boundaries or saying no and giving a better choice for a reward?