She learns how to be a good friend to Sal and others. She learns how to be compassionate. She also learns about time. All of this gives Miranda a brand new perspective – or way of seeing the world.
The correct answer is "Slang displays a tone that is too casual"
Slang speak is highly informal, sometimes even offensive. One should never use slang in a business setting because business deals should be kept highly informal and professional. Slang shouldn't be used under any circumstance as it may insult the people with whom we are talking by making it seem that we don't appreciate them or their business endeavors.