'Significant others' are

a) friends

b) peer group

c) parents

d) police

In social psychology 'a significant other' is the parent, uncle, grandparent, or teacher - the person that guides and takes care of a child during primary socialization. The significant other protects, rewards and punishes the child as a way of aiding the child's development. This usually takes about six or seven years, and after that the significant other is no longer needed, the child moves on to a general other which is not a real person, but an abstract notion of what society deems good or bad.

So option (c) is the correct option here.