Question: What line is missing from this code?

1. `let vowels = "aeiou".toArray();`
2. `let vowels = Array.of("aeiou");`
3. `let vowels = {"a", "e", "i", "o", "u"};`
4. `let vowels = "aeiou";`

Answer: The correct answer of the above question is Option D:`let vowels = "aeiou";`