The correct answer is C and I'm not sure how they got this,
could you please...
the WW Relative Count Rate mler - 14.4 keV 57Fe -4-3-2-1 0 1 2 3 4 Velocity (mm/s) 100. A room temperature Mössbauer absorption spectrum for the 14.4 keV gamma-ray transition of "Fe is illustrated in the figure above. From the data, it can be deduced that the lifetime of the excited state is approximately (A) 100 ms (B) 100 us (C) 100 ns (D) 100 ps (E) 100 fs