• Plant Trace Element Concentrations:
• Manganese (Mn): Typical physiological requirement in plant tissue ranges around 0.1 to 0.5 ppm in solution culture $\rightarrow$ (I)
• Molybdenum (Mo): The lowest required micronutrient, functioning in nitrogen metabolism around 0.01 to 0.05 ppm $\rightarrow$ (III)
• Iron (Fe): Required in the highest relative concentration among micronutrients for chlorophyll synthesis and redox chains, typically 0.5 to 5.0 ppm $\rightarrow$ (IV)
• Zinc (Zn): Essential for auxin synthesis and enzyme activation, maintained around 0.02 to 0.2 ppm $\rightarrow$ (II)
• Systematic Match: (A)-(I), (B)-(III), (C)-(IV), (D)-(II) (Option 3).

Correct option: (3) (A) - (II), (B) - (Ill), (C) - (IV), (B) - (1)

• Antagonistic Action of ABA on Gibberellin: In germinating cereal seeds (barley, wheat), gibberellins (GA) induce the de novo transcription of hydrolytic enzymes (such as $\alpha$-amylase) in the aleurone layer by promoting GAMYB expression.
• Suppression Mechanism: Abscisic acid (ABA) directly suppresses this GA-mediated induction by activating protein kinases (such as PKABA1) and transcriptional repressors that silence the $\alpha$-amylase promoter, thereby maintaining seed dormancy.

Correct option: (3) Abscisic acid

• Function of Amyloplasts: Amyloplasts are non-pigmented plastids (leucoplasts) specialized for the polymerization and long-term storage of starch (amylose and amylopectin) in nutrient storage organs such as roots, tubers (potatoes), and seed endosperms.
• Plastid Specializations: Proteinoplasts/aleuroplasts store proteins, while elaioplasts store lipids/oils. Amyloplasts in root columella cells also serve as statoliths for gravity perception (gravitropism).

Correct option: (2) Storage of starch