An observer views four identical clocks that are traveling at speeds close to the speed of light. can observations of the passage of time be used to rank the clocks according to their speeds? a. yes. the clock that shows the fastest passage of time is traveling the fastest. b. yes. the clock that shows the slowest passage of time is traveling the fastest. c. no. the passage of time on the four clocks should be the same, regardless of speed. d. no. the passage of time on each clock depends on the frame of reference of the observer.