How do you create a variable in JavaScript?

In JavaScript, creating a variable can be done using several keywords, among which "var" is one of the most traditional ways. The declaration var number = 100; correctly initializes a variable named number and assigns it the value 100.

Using var has implications regarding scope, as it defines a variable that is function-scoped or globally-scoped, meaning that it can be accessed anywhere within the function it’s defined in or globally if declared outside of any function. This makes it important when considering how and where the variable can be used within your code.

While there are other modern ways to declare variables, such as using let or const, which provide block-scoped variable declarations, the option highlighting var is a valid and traditional method to create a variable in JavaScript. Options that do not comply with the correct syntax, or do not use recognized keywords for variable declarations, are not valid for this context.