Final answer:
The line "Be afraid... be very afraid" is from the horror movie The Fly, not The Shining, Psycho, or The Conjuring.
Step-by-step explanation:
The classic line "Be afraid... be very afraid" comes from Option 3: The Fly. This film debuted in 1986 and is known for its innovative special effects and haunting dialogue. Although The Shining and Psycho are also well-known horror films, they do not feature this iconic line. Similarly, The Conjuring is a more recent entry to the horror genre and does not contain this specific quote.