Antonyms are words with exactly the opposite meaning. Friendly means well-disposed, behaving or acting as a friend, amicably. On the other hand, hostile means acting as an enemy, in an unpleasant and non-friendly way.
Pleasant and welcoming would be, in a way, synonyms for friendly - that is, words with the same or similar meaning. Timid means shy or fearful, so it has nothing to do with friendly.
Hostile is quite the opposite of friendly. It means to be unpleasant or rude. Timid also cannot be the correct answer because it means that a person is shy or easily scared. Lastly, welcoming cannot be the answer because a person does not need to greet/welcome somebody in order to appear friendly.
I hope this helps answer your question! Have a great day!
