Copper (I): Deficiency causes Dieback (Exanthema) in Citrus. Match: I - D - W.
Boron (II): Deficiency causes Heart-rot (Brown heart) in Beet. Match: II - C - X.
Molybdenum (III): Deficiency causes Whiptail disease in Cauliflower. Match: III - B - Y.
Nickel (IV): Deficiency causes Mouse ear in Pecan (leaves become small and rounded). Match: IV - A - Z.
Step 2: Select Option:
The sequence matches Option (A).