Which of the following is an example of a keyword in BASIC programming?

In BASIC programming, keywords are predefined words that have special meaning within the language and are reserved for specific functions. The option "IF" is a keyword used for control flow, allowing the programmer to execute certain blocks of code based on conditions. For instance, when using "IF," the programmer can define a logical condition that, when true, will result in specific actions being executed, enabling decision-making within the program.

The other choices provided do not function as keywords in BASIC. "START" is not a recognized keyword in BASIC; it might imply a starting point, but it does not have a defined role within the language syntax. "VARIABLE" is a term used in programming to denote a storage location but is not a keyword itself, nor does it perform operations. Similarly, while "FUNCTION" pertains to defining a set of instructions that can be reused, it is not explicitly a keyword in BASIC; instead, functions may be defined using specific keywords like "FUNC" in some versions or by defining subroutines. Thus, "IF" stands out as the appropriate keyword that dictates control flow conditions in BASIC programming.