Answer:
Morrison’s radio broadcast is a primary source.
Step-by-step explanation:
From the ground, reporting on the arrival of the zeppelin was conducted by American journalist Morrison. He witnessed the catastrophe of the zeppelin.
Primary source is information collected for the first time. Secondary data is information that already exists somewhere, being previously collected for other purposes. This difference is reflected in the existence of two different terms - desk research to collect secondary data and field research. Accordingly, Morrison's report is the primary source.