Why is mobile app development important?

The answer to this is letter D. To create the validation rule, the not equal operator should be used. Do you understand what a validation rule is? This is used in order to verify the information that has been placed in the record all meet the standards that have been set prior.

There are different formulas or expressions that can be placed so that true or false may appear in some of the fields wherein the standards are placed. Without this, it will be hard to see if the data is valid enough for what is being measured. There are different ways that you can design that data validation rules that are available.