Answer:
a) 弦 -> 畜 -> 胃 -> 脹
弦 GEN, tsuru - string, bowstring
畜 CHIKU - animal raising, domestic animal
胃 I - stomach
脹 CHOU - swell
b) 勅 -> 加 -> 員 -> 贈
勅 CHOKU - imperial decree
加 KA, kuwa(eru), kuwa(waru) - add, append, join, take part
員 IN - member
贈 ZOU, SOU, oku(ru) - give, present, bestow