Correct option is D
Given: LG_ALL_FBL_GF_LLGF_L
Logic: We have to put each option in the blank space when any option gives us a proper logical series that will be correct option.
From option (a):FFCCD
LGFALLFFBLCGFCLLGFDL (not follows logical pattern)
From option (b):FCGLD
LGFALLCFBLGGFLLLGFDL (not follows logical pattern)
From option (c):FLGDC
LGFALLLFBLGGFDLLGFCL (not follows the logical pattern)
From option (d):FGLCD
LGFAL /LGFBL/ LGFCL/ LGFDL (follows logical pattern)
(Fourth letter inceresing by +1 )
Thus, correct option is (d).