Two FBGs are used to measure both strain and stress at one location: To sensing module Anchor points FBG A FBG B The sensitivity of the FBGS to temperature and to strain are 20 pm/C and 2 pm/uz, respectively. (a) If the structure experiences compression of 50 e, what are the Bragg wavelength shift for FBG A and FBG B? (please indicate + or - sign). (b) If the temperature at the location increases by 20 C, what are the Bragg wavelength shift for FBG A and FBG B? (please indicate + or - sign). (c) If the Bragg wavelength shift for FBG A and FBG B are 2 nm and 1.5 nm, respectively, what are the change in temperature and strain at the location?