What should you use to update the “Full days of Rent” field on the Power Apps form?

Answer options:

A.Business rule
B.Business Process flow
C.Power Automate
D.Client script
E.Dataverse plug-in

Correct Answer: D 
When a user provides the car return date, RentMe model-driven application updates the "Full days of rent" field on a form. The easiest way is to use the business rules to do that. But the business rules are working on the form load or refresh. The JavaSript or Typescript client script is the best way to update the form in "real-time" after the input of the return date. The script must calculate the full days of rent and update the "Full days of rent" field on a form. 
All other options are incorrect. 
For more information about the use of the client scripts in model-driven apps, please visit the below URLs: 

https://docs.microsoft.com/en-us/powerapps/developer/model-driven-apps/client-scripting
https://docs.microsoft.com/en-us/learn/modules/automate-business-process-flow-client-script-power-platform/2-best-practices