The FlexCard functionality that can be used to meet this requirement is Conditional View. A Conditional View is a property that determines whether a FlexCard element, such as a field or an action, is visible or hidden based on certain conditions. The consultant can use a Conditional View to show or hide the reopen case action based on the status of the case

Explanation
The OmniStudio tool that the consultant should recommend to meet this requirement is Grouped Calculation Matrix. A Grouped Calculation Matrix is a tool that can perform complex calculations based on multiple input variables and output values within groups. The consultant can use a Grouped Calculation Matrix to define the input variables, such as state and other factors, and the output values, such as rates. The Grouped Calculation Matrix can then apply rules and formulas to calculate the rates for each state separately, but using the same formula

Explanation
The two OmniScript features that the consultant should recommend to meet this validation requirement are:
Messaging and Formula. A Messaging element is an element that can display a text message with an icon and a color, such as blue for information or yellow for warning. The consultant can use a Messaging element to display an error message stating that the age cannot be less than 18 if the user's birthday indicates they are under 18 years old. A Formula element is an element that can perform calculations or validations on data values using expressions or functions. The consultant can use a Formula element to validate the user's birthday by subtracting it from the current date and checking if the result is greater than or equal to 18 years