C. By adding a disclaimer at the beginning of the show
Because the topic of alien invasion was a hot topic around
the time _War of the Worlds_ came out, it was very possible and very plausible that
those listening to the radio program would, in fact, believe what they were
listening to were real-life events and not a science-fiction piece. As such, at the beginning of the radio
program, there was a disclaimer that preceded the show that informed listeners
that what they were about to hear was not real.
However, those who happened to tune in late and happened to miss the
disclaimer, and many believed that what they were listening to was actually
happening.
