Why is the phrase "duck and cover" repeated many times throughout the
video?

A. To show students that it was very hard and complicated to be safe
during an atom bomb attack.

B. To show students that it was very simple and easy to be safe
during an atom bomb attack.

c. To show students that is was not possible to be safe during an
atom bomb attack

D. To show students that an atom bomb attack was veryhoangerous.