Answer:
努 -> 加 -> 員 -> 贈
努 DO, tsuto(meru) - exert self, make efforts, strive
加 KA, kuwa(eru), kuwa(waru) - add, append, join, take part
員 IN - member
贈 ZOU, SOU, oku(ru) - give, present, bestow
菓 -> 林 -> 森 -> 禁
菓 KA - cake, fruit
林 RIN, hayashi - woods
森 SHIN, mori - forest
禁 KIN - prohibition