Which of the following inferences about avionics is best supported by the passage? A. Within a decade, passenger planes will take off and land without human intervention. B. Soon passenger planes will include features that now appear only on military planes. C. Just 40 years ago, there were no electronic devices on passenger airplanes. D. As avionics becomes more common, the cost of manufacturing planes will decrease. E. A glitch in a plane's electrical system may be the greatest danger in flight today.