2176. What characters can be added here so that each character contains a part of the previous character? a) 菓 -> _ -> _ -> 胞 b) 篤 -> _ -> _ -> 財

a) 菓 -> 棋 -> 期 -> 胞  

菓  KA - cake, fruit

棋  KI - go, shogi, Japanese chess

期  KI, GO - time, period, term

胞  HOU - sac, sheath, placenta

b) 篤 -> 駐 -> 責 -> 財  

篤  TOKU - serious, cordial

駐  CHUU - stop, reside

責  SEKI, se(meru) - condemn, censure, torture

財  ZAI, SAI - money, wealth, property