A. var defines a variable while let defines a constant.
B. There is no such major difference between them
C. The value of variable declared with let cannot be changed
D. var define function scoped variable while let define block scoped variable

Solution

D. var define function scoped variable while let define block scoped variable

Explanation

var: Variables declared with var are function-scoped. This means they are only accessible within the function where they are declared. If a variable is declared outside any function, it becomes a global variable.

let: Variables declared with let are block-scoped. They are limited to the block, statement, or expression where they are declared. This includes loops, conditionals, and functions.