B is the mother of A. A is the sister of C. C is the father of D. How is B related to D? MCQ with Answer and Explanation

Explanation:
Doctors are graduates, but not necessarily among the graduates who are teachers. No definite relation.

Explanation:
Each letter is shifted two places forward: R→T? Wait R+2=T. Let's check OCEAN: O+2=Q? O is 15 +2=17 Q, not P. Need fix. Use shift +1? O→P, C→D? C+1=D not E. Pattern not valid. Better replace question. Use simple shift +1: OCEAN → PDFBO? O+1=P, C+1=D, E+1=F, A+1=B, N+1=O = PDFBO. Then RIVER → SJWFS. We'll not use that broken question. Instead create valid coding.

Explanation:
Letters increase by 3: C,F,I,L,O. Numbers are squares: 2²=4,3²=9,4²=16,5²=25,6²=36.