Let us correctly match each traveler with their respective country:
a. Afanasi Nikitin – A traveler from Russia who visited India in the 15th century. II
b. Domingo Paes – A Portuguese traveler who visited the court of Krishnadevaraya in Vijayanagara. III
c. Abdur-Razzak – A Persian ambassador and chronicler who visited South India during the 15th century. I
d. Nicolo de Conti – An Italian merchant and traveler who visited parts of India. IV
Thus, the correct matching is: a–II, b–III, c–I, d–IV.