Choice A rationaleSunken fontanels are typically a sign of dehydration due to reduced intracranial pressure and are not specific to abusive head trauma. Abusive head trauma often results in elevated intracranial pressure or swelling, which would present differently. Therefore, this finding is unrelated to the mechanisms of abusive head trauma in a 2-month-old.Choice B rationaleRetinal hemorrhages are strongly associated with abusive head trauma due to the shearing forces during shaking or impact, which rupture retinal blood vessels. This finding is a hallmark of non-accidental trauma in infants, as accidental injuries rarely cause this degree of internal ocular damage.Choice C rationaleLarge bruises on the body could indicate trauma but are not specific to abusive head trauma. Additionally, the pattern or location of bruises is significant for abuse, especially in non-mobile infants. However, bruises alone do not confirm head trauma specifically.Choice D rationaleLacerations, such as those on the forearm, might suggest trauma but lack specificity for abusive head trauma. Such injuries are more commonly associated with accidents or other forms of physical abuse that do not necessarily involve the head.