The original code passes the world function object itself as the name argument to sayHello. Consequently, console.log prints the function's definition. To print the result of the world function, it must be invoked. Changing line 2 to console.log('Hello', name()); invokes the passed function (name which holds world), retrieves its return value 'World', and logs the desired "Hello World" message.

B. This creates a syntax error. An Immediately Invoked Function Expression (IIFE) would require a different structure, such as const world = (() => { return 'World'; })();.

C. The sayHello function does not return a value (it returns undefined), so attempting to invoke its result with () will cause a TypeError.

D. Changing the function declaration syntax from an arrow function to a standard function does not change the fact that the function object itself is being passed, not its return value.

1. MDN Web Docs, "Functions", Section: "Function parameters". This documentation explains the difference between passing a function reference and invoking a function with ().

2. ECMAScript® 2023 Language Specification, Section 13.3.1 "Arrow Function Definitions". This details the syntax and evaluation of arrow functions, showing that the original code is syntactically correct but logically flawed for the intended output.