Which statement specify correct difference between var and let keywords in JavaScript ?

कौन सा कथन जावास्क्रिप्ट में var और Let कीवर्ड के बीच सही अंतर निर्दिष्ट करता है?

var defines a variable while let defines a constant.

There is no such major difference between them.

The value of a variable declared with var can be changed while the value of a variable declared with let cannot be changed.

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

Explanation: