Answer:
a) 劣 -> 加 -> 吐 -> 堀
劣 RETSU, oto(ru) - be inferior
加 KA, kuwa(eru), kuwa(waru) - add, append, join, take part
吐 TOU, ha(ku) - spew, vomit, give vent to
堀 hori - moat, canal, ditch
b) 篤 -> 駐 -> 責 -> 贈
篤 TOKU - serious, cordial
駐 CHUU - stop, reside
責 SEKI, se(meru) - condemn, censure, torture
贈 ZOU, SOU, oku(ru) - give, present, bestow