Answer:
A. Call the parent so that you can insert positive comments as well as the negative event.
Step-by-step explanation:
Option A is the best action you should take to inform a negative event. This type of circumstances need to be informed personal, because emotions are involved. So, waiting a long time period to inform about it, or doing through a non-direct channel means that you don't give the importance that this event needs. Also, that wrong actions will make parents think that it's not important to you.