Final answer:
The answer to how often a pedestrian is killed in an intersection nationwide according to NHTSA cannot be determined without current specific data from NHTSA reports or official statistics.
Step-by-step explanation:
The question provided asks about the frequency at which pedestrians are killed in intersections nationwide. According to the National Highway Traffic Safety Administration (NHTSA), the correct frequency is not explicitly stated in the provided reference information; therefore, without current and specific data from NHTSA reports or official statistics, we cannot accurately answer whether it is a) every 60 minutes, b) every 90 minutes, c) every 111 minutes, or d) every 120 minutes. To answer this question with certainty, one should consult the latest NHTSA traffic safety facts or official publications for the most current pedestrian fatality statistics.