Which keyword starts a logical test in an IF function?

The keyword that starts a logical test in an IF function is "IF." This function is fundamental in Excel for making decisions based on conditions. When you construct an IF statement, you use "IF" to introduce the logical test you want to evaluate. The syntax for an IF function generally follows this structure: IF(logical_test, value_if_true, value_if_false).

In this context, the logical_test is the expression that is evaluated to determine whether it is true or false. The use of "IF" allows users to create branching paths in their formulas, providing flexibility and enabling complex calculations based on specific criteria. Understanding this concept is crucial for effectively using Excel to analyze data and automate decision-making processes.

The other options do not serve as the initiating keyword for the logical test within an IF function. "THEN" is a common term in programming languages to denote the next step after a condition is met, but it doesn't apply to Excel's IF function. "CASE" is used in different contexts, such as in a SWITCH or CASE statement in programming, but it is not part of Excel’s IF function syntax. "LOGICAL" refers to the type of test applied but is not the keyword that begins the function.