$6.$ In the Projects table, Hwan wants to make sure that everyone entering project information enters the correct project categories, which are listed in the range I$4$:I$7.$ He asks you to ensure users enter a value from this range.

a$.$ Select the data in the Categories column, and create a data validation rule that accepts only List values from the categories in column I. Use a range reference instead of writing the categories themselves.

b$.$ Create an input message that uses Project Category as the title and the following text as the input message:

Enter a project category.

c$.$ Create a Stop style error alert that uses Invalid Category as the title and the following text as the error message:

Enter a category listed in column I.