A is B's sister. C is B's mother. D is C's father. E is D's mother. How is A related to D? MCQ with Answer and Explanation

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:
Some cats are black and all black things are beautiful, so those black cats are beautiful.

Explanation:
First letters increase A, B, C, D, E; second letters decrease Z, Y, X, W, V.