Iron deficiency causes:
Go with B — Interveinal chlorosis of young leaves. Under MINERAL Transport, this is the standard explanation you’d use in class: it names the real driver or definition, while the rest are nearby but wrong. Not these: A) Uniform chlorosis; C) Necrosis of old leaves; D) Leaf curling. When two options sound similar, choose the one that matches the textbook definition most tightly.
Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.