Ans: A (Craving) Ref: Kaplan and Sadock's Comprehensive Textbook of Psychiatry, 9th editionExplanation:AddictionIt is a lay-man term no longer preferred in medical literature.There is a range in the use of any substance (here "substance" is the term denoting anything which has some effect on body, usually brain) viz., - misuse (excessive, unwarranted use of medicines). harmful use (persistent use despite adverse health problems due to substance), abuse (persistent use despite adverse social/financial consequences).DependenceIt is a broader term covering above plus others.Two types of dependence noted:o Psychico PhysicalPsychic dependence is characterised by:o Craving: Craving denotes excessive,''persistent desire to use the substance,o Loss of control.Physical dependence is characterised by:o Tolerance (higher amount of substance needed to produce the original effect/kickl).o "Withdrawal symptoms'" (unique for each substance),o Dependence is a syndrome covering all (as per ICD-10, 3/6 criteria is enough for it).CompulsionIt is a repeated activity mostly due to an obsession.It is seen in OCD. where the person considers his compulsion as irrational (ego-dystonic)ImpulseIt is an irresistible urge to do something (usually harmful to self/others).Impulse- control disorders (ICD) are a group of disorders characterised by repetitive impulsive behaviour like pyromania, pathological gamblingCompulsion Vs ImpulseThe key difference between compulsion and impulse is the aim of the act- in compulsion the aim is to get rid of the anxiety and in impulse - no aim at all or a pleasure.Even though "repetitive" behaviour is common and central theme in all these three (Substance abuse, OCD, ICD) compulsion and impulse are not used in substance psychology widely and that too in same meaning.