Answer:
a) 駐 -> 素 -> 紛 -> 頒
駐 CHUU - stop, reside
素 SO, SU - element, naked, simple
紛 FUN, magi(reru), magi(rawashii) - be mistaken for, confusing
頒 HAN - divide, distribute
b) 動 -> 加 -> 呈 -> 球
動 DOU , ugo(ku) - move
加 KA, kuwa(eru), kuwa(waru) - add, append, join, take part
呈 TEI - offer, present, exhibit
球 KYUU, tama - ball, sphere