Quick answerHigh-dose IV thiamine now.
Why this is correctThe confusion tempts a withdrawal answer, but the data do not fit withdrawal delirium: vitals are normal and CIWA-Ar is 7, below the protocol threshold of 10. The triad of confusion, ataxia, and nystagmus fits Wernicke encephalopathy, which needs IV thiamine at high doses right away.
Easy analogy or mental pictureWithdrawal is an engine racing (fast HR, high BP, tremor); Wernicke is an engine out of fuel (confused, wobbly, eyes jerking) and thiamine is the fuel.
Memory hookConfused + wobbly + eyes jerk, vitals calm = THIAMINE IV, fast.
NCLEX decision ruleBefore treating confusion in alcohol use disorder, check whether the vital signs and withdrawal score actually support withdrawal.
Why the other choices are wrongLorazepam per CIWA-Ar is correct for withdrawal, but the score of 7 is below the protocol threshold and extra sedation would mask the neurologic picture. Haloperidol is sometimes used for agitation, but this client is confused rather than agitated, and it lowers the seizure threshold. Oral thiamine 100 mg is standard prevention for at-risk clients, so it looks right, but once signs of Wernicke appear, oral absorption is unreliable and the dose is far too low.
References
1StatPearls: Wernicke EncephalopathyConfusion, ataxia, and ophthalmoplegia/nystagmus require prompt parenteral high-dose thiamine
2ASAM Clinical Practice Guideline on Alcohol Withdrawal ManagementSymptom-triggered benzodiazepine dosing is based on withdrawal severity scores; thiamine for at-risk clients