B: UpdateContext function can be used to create a variable that is only available to the current screen. This function takes in an object that defines the variable and its initial value, and updates the context of the current screen with that variable. Reference: https://docs.microsoft.com/en-us/powerapps/maker/canvas-apps
/functions/function-updatecontext
C: Set function can be used to assign a value to a variable. The Set function sets a variable to a specified value, which is useful when you need to update the value of a variable. Reference: https://docs.microsoft.com
/en-us/powerapps/maker/canvas-apps/functions/function-set