Concept:The correct word must describe the early years when a child's character is being shaped.Explanation:"Formative years" is the standard expression for the period of childhood when personality and character develop."Restrained" means controlled or limited, which does not fit the context."Constructive" means helpful or useful, not related to early life stages."Conflicting" means clashing or opposing, which is also incorrect here.Therefore, the only suitable word is "formative".Answer:D. formative