The InputBox functions prompt argument should be entered using . . . . . . . .

The correct answer is: C. Text capitalization.

The InputBox function is a VBA function that displays a dialog box that prompts the user for input. The prompt argument is the text that is displayed in the dialog box. The prompt argument should be entered using text capitalization, which means that the first letter of each word should be capitalized, except for articles (a, an, the), coordinating conjunctions (and, but, for, or, nor, so, yet), and prepositions (at, by, for, in, of, on, to, up, with).

Here are some examples of text capitalization:

• The quick brown fox jumps over the lazy dog.
• I am a student at the University of California, Berkeley.
• My favorite color is blue.

Here are some examples of incorrect capitalization:

• the quick brown fox jumps over the lazy dog
• i am a student at the university of california, berkeley
• my favorite color is blue

It is important to use text capitalization when entering the prompt argument for the InputBox function because it makes the text more readable and easier to understand.