His friends begin to criticize marco as a "boozer," pushing him out of their social circle. marco begins to drink even more becomes bitter, and joins a new group of friends who also are heavy drinkers. according to lemert, marco's situation illustrates:

Following is missing for the question to be complete:

a. the onset of primary deviance.

b. the onset of secondary deviance.

c. the formation of a deviant subculture.

d. the onset of retreatism.

   B. The onset of secondary deviance

Explanation:  According to Lemert, secondary deviance begins and develops when one's behaviour is labelled as deviant by other members of the group or society, which may be yesterday's friends who for some reason begin to regard one's behaviour as deviant. After such treatment by the group members, the behaviour of the marked "deviant" member begins to change exactly in the direction that the other members of the group marked. Then the secondary deviation begins. Maybe the labelled "deviant" member, Marco, wasn't really that deviant, or in this case the boozer, but he starts to take the marked behaviour even as an act of rebellion against the other members of the group who tagged him, he may end up leaving that group and joining a group that is truly deviant, i.e a boozer group.

the first question's answer is a.