Answer: c. ridicule and ostracism from a group of former friends.
Explanation:
Informed sanctions are the rules or norms that are unwritten and these are not enforced by any government authority.
The informal sanctions cannot be considered as laws in legal sense, instead these are the rules and regulations developed by the society or individual. A boycott against some service, goods and particular group of society comes under the informal sanction.
The ridicule means to say unkind words to someone and ostracism means to avoid or exclude oneself or others from the group. The ridicule can be used to show ostracism or exclusion from the group of former friends can be consider as an example of boycott. Thus this can be consider as informal sanction as no laws are involved but social rules and regulations are prominent.
