In a Test of Equipment the Following Procedure Is Carried

Multiple Choice

In a test of equipment the following procedure is carried out.Spacecraft №1 is traveling at 0.75c and fires a laser pulse in the forward direction at Spacecraft №2,which is testing its device that measures the speed of laser pulses as they pass by the spacecraft.Spacecraft №2 is traveling at 0.95c in a direction away from Spacecraft №1.The device is working properly,and the speed of the pulse as it passes is successfully measured.What is the speed of the laser pulse measured in this case?

A) 0.80c
B) 0.70c
C) c
D) This is a question that cannot be answered without knowing in which reference frames the speeds given in the problem.If you agree,then this is the answer that you should choose.