Answer:
a) 早 -> 古 -> 呈 -> 球
早 SOU, SA, haya(i) , haya(meru) - early, fast, hasten
古 KO, furu(i) - old
呈 TEI - offer, present, exhibit
球 KYUU, tama - ball, sphere
b) 如 -> 吐 -> 域 -> 惑
如 JO, NYO - equal, like, as, as if
吐 TOU, ha(ku) - spew, vomit, give vent to
域 IKI - region, area
惑 WAKU, mado(u) - go astray, be tempted