ABD : DGK : HMS :: MTB : SBL : ?
XKW
ZAB
ZKW
None of these
A+3−→D+4−→H+5−→M+6−→S+7−→Z
B+5−→G+6−→M+7−→T+8−→B+9−→K
D+7−→K+8−→S+9−→B+10−−→L+11−−→W