What setting must be enabled for the process model to check process variables for values prior to starting?

The setting that must be enabled for the process model to check process variables for values prior to starting is related to the use of parameters. Initiating a process model with specific values checked beforehand ensures that the necessary conditions are met before the process begins its execution. This capability is typically controlled by parameters, which allow you to set specific values that the process model can reference upon initiation.

When parameters are enabled and properly configured, the process model can evaluate incoming values for the defined process variables. This is essential in scenarios where the behavior of the process is contingent upon certain pre-defined values. It ensures smooth execution and minimizes the chances of errors that could arise from missing or incorrect data when the process starts.

Other choices may seem relevant but do not specifically facilitate the checking of process variable values before initiation. Understanding the role of parameters in this context is key to effectively managing process execution in Appian.