What happens after clicking a button with this code?

btn.addEventListener('click', function(e) {
  e.target.style.background = 'blue';
});

Given:

const arr = [1,2,3,4];
const result = arr.filter(x => x % 2 === 0).map(x => x * 10);

What will the console output?

function change(obj) { obj.value = 10; }
const obj = {value: 5};
change(obj);
console.log(obj.value);

Given:

const a = { value: 10 };
const b = a;
b.value = 20;

Result of this code?

const nums = [1,2,3,4,5,6];
const even = nums.filter(x => x % 2 === 0);
console.log(even);

Context:

const profile = { name: "Sara", age: 30 };
const copy = profile;

Which of the following modifies both profile and copy?