The correct answer is D) find a time and place where you can take the person aside and discuss the situation calmly.
If you find yourself in conflict with a coworker, the first step you should take to resolve the problem is to find a time and place where you can take the person aside and discuss the situation calmly.
You want to resolve the conflict not making it bigger. That is why you need to keep calm and have a decent but serious conversation with your coworker in order to understand what is affecting him/her or what makes him/her rude to you. You show respect and calm because probably you are going to hear things that don't like you or are not true. Then you have to do the same and tell the coworker what you think.