Which of the following conclusions is consistent with the predictions of social impact theory?

Which of the following conclusions is consistent with the predictions of social impact theory?
 
  a. Conformity is more likely among groups of strangers than within established groups that are important to us.
  b. Social influence increases in a linear fashion as a group grows in size; in other words, each new member added to a group adds the same amount of social influence as the previous member added.
  c. The more immediate a group is, the more social influence it tends to exert.
  d. Conformity is less prevalent in collectivist cultures than it is in individualistic cultures.