To solve this question, we need to match the items in List-I with the correct personalities associated with each concept in List-II. Let's go through each pair:

1. Primary group: This concept is famously associated with Charles Cooley, who introduced the idea of 'primary groups' as small social groups whose members share close, personal, and enduring relationships. Thus, the correct match is:

a. Primary group - iv. Charles Cooley

1. Reference group: These are groups that individuals use as a standard for evaluating themselves and their own behavior. This concept is most closely linked with Hyman, R. Therefore, the correct match is:

b. Reference group - iii. Hyman, R

1. In-groups and Out-groups: These terms are associated with the work of William Graham Sumner, who categorized social groupings in terms of 'us' versus 'them'. Thus, the match is:

c. In-groups and Out-groups - i. Summer, W.G.

1. Organised group: The concept of organized groups is linked with Robert Bierstedt, known for his work on social organization and structure. Hence, the correct match is:

d. Organised group - ii. Bierstedt, Robert

After matching the items, the correct code based on the options given is:

a-iv, b-iii, c-i, d-ii

This matches the provided and confirmed correct answer. Therefore, the correct answer is option: a-iv, b-iii, c-i, d-ii.