The correct answers are C and D.
Arrays in JavaScript are objects. When an array variable is assigned directly to another variable, both variables point to the same array in memory.
Option C is correct:
let arr2 = arr;
This does not create a new array. It creates another reference to the same array.
Example:
arr2.push(6);
console.log(arr);
Output:
[1, 2, 3, 4, 5, 6]
Changing arr2 also affects arr because both variables reference the same array.
Option D is also correct:
let arr2 = arr.sort();
The sort() method sorts the array in place and returns the same array reference. Therefore, arr2 refers to the same array object as arr.
The incorrect options create copies:
let arr2 = arr.slice(0, 5);
creates a shallow copy.
let arr2 = Array.from(arr);
also creates a new shallow copy.
So the two lines that make arr2 reference the original arr are C and D.