In verbal, you should always have a look at the options. If they ask the antonym of ‘beautiful’ and say you don’t know the meaning of it. You can look at the options that may read
1. Ugly
2. Smart
3. Handsome
4. Good looking
In the given options, if you know that choices 2, 3 and 4 mean same thing, then you can blindly go for the first one.