An alien spacecraft is flying overhead at a great distance as you stand in your backyard. You see its searchlight blink on for 0.190 s. The first officer on the spacecraft measures that the searchlight is on for 12.0 ms. Which is the right statement about the measurement?
A、The time of 0.190 s measured by you is the proper time.
B、The time of 12.0 ms measured by the first officer on the craft is the proper time.
C、The proper time is smaller than 12.0 ms
D、Based on these measurements, the speed of the spacecraft can be calculated.