Typically, Jasmine arrives earlier than A. us.
The correct answer is A.
This is because you need to use an objective pronoun - the word us is an object of this sentence, and the pronoun we can only be used as a subject. Just substitute the last pronoun with I (subject pronoun) or me (object pronoun). You'd definitely say - She arrived earlier than me (and not than I), and thus you know it is an object, not a subject.