The losses caused due to hydrogen absorption mechanisms are in the range of ___________

Optoelectronics and Optical Communication 

The losses caused due to hydrogen absorption mechanisms are in the range of ___________

a) 20 dB/km to 25 dB/km
b) 10 dB/km to 15 dB/km 
c) 25 dB/km to 50 dB/km 
d) 0 dB/km to 5 dB/km

Answer : - 25 dB/km to 50 dB/km