Social and cultural references in Sangam literature

Statement (b) is correct; while the rigid Northern caste system was not fully entrenched, the conceptual classification of Varna (Arasar, Anthanar, Vanigar, Vellalar) was definitely known and referenced by Sangam poets (e.g., in the Tolkappiyam). Statements (a) and (c) are blatantly false; Sangam poetry is extraordinarily rich in detailing material trade and intensely glorifies the warrior ethic (Puram poetry).

Answer: (b).