Final answer:
Excel's formula checker verifies the syntax of formulas, ensuring they are structured correctly for proper execution.
Step-by-step explanation:
Similar to the spell checker, Excel has a formula checker that checks formulas in a worksheet for rule syntax. The correct answer to the question is b) Syntax. This feature helps users identify any errors in the structure of their formulas, ensuring that the formulas will work correctly when executed. This is essential because unlike spelling, punctuation, or grammar which are more textual content-focused, formulas require a strict adherence to syntactical rules for the program to understand and execute them.