Match Single Character with Multiple Possibilities problem

Tell us what’s happening:
Whats wrong with this code ? Why he doesn’t wrong.Thank you for answering)

Your code so far

let quoteSample = "Beware of bugs in the above code; I have only proved it correct, not tried it.";
let vowelRegex = /[a, e, i, o, u]/ig; // Change this line
let result = quoteSample.match(vowelRegex); // Change this line

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 6.2; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.87 Safari/537.36.

Link to the challenge:

Read the lesson again carefully. You do not have your character class group set up correctly.

[aiu] is the character class that will only match the characters "a", "i", or "u".