Why does an arrow function method return undefined for this?

Do you know what will be the output of this code?

const obj = {
  value: 42,
  regular() {
    return this.value;
  },
  arrow: () => this.value,
};

console.log(obj.regular(), obj.arrow());

1. 42 42
2. 42 undefined
3. undefined 42
4. TypeError