Correct option is B
Patients on disulfiram must strictly avoid alcohol in any form (including OTC medicines, mouthwash, aftershaves) to prevent severe disulfiram–alcohol reaction.
Explanation of options: (a) ✘ Even small amounts can trigger severe reaction. (b) ✔ Correct; avoid all alcohol-containing products. (c) ✘ Craving control is not indication to stop drug. (d) ✘ Increasing dose is dangerous, never advised.