[单选题]
Which of the following depends on gg tl 3b0,jswe ac.g35.q) nrtrdc: d7ck/ 4shthe observer's frame of reference?tqp835jy hxs76o;k l9w 3gv j6stb7 yl
A. the mass of the proton
B. the length of a meter stick
C. the half-life of a muon
D. all of the given answers
