If You Are First on Scene,what Should You Do First

If you are first on scene,what should you do first in determining where and how should you park your apparatus?

A) Establish Command and confirm the exact location of the incident with the dispatch center before parking.
B) Use apparatus to institute "downstream blocking" of the scene to protect the work area.
C) Immediately park in the same direction and in single file.
D) Provide downstream blocking if you are driving one of the larger units.