nayana-c1.867c992ae9100904cc61c84591adf0f8f863e0387e30f0d0dbc86640e9f50a1a.en.validation.28906

The task

What is the main reason the aircraft's position at the time of the first signal cannot be accurately determined? A. The signal was too weak to be recorded accurately. B. There is no record of the exact time of occurrence or elapsed time to allow for back-calculation. C. The aircraft was flying at an unknown speed. D. The equipment used to detect the signal was faulty. Return only the single uppercase letter of the correct option.