Major site of water absorption in roots is:
Pick C: Root hair zone. Thinking through WATER TRANSPORT step by step rules out the lookalikes and leaves Root hair zone. Skip these: A) Root cap; B) Mature region; D) Meristem. For hormones and genes, match the molecule or gene to its real role, not a neighboring pathway.
Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.