Correct option is A
The correct phrase is "little in common," which means that Ravi and his friend Senthil do not share many similarities or interests.
· The other options do not fit the context of the sentence:
· "Contention" means disagreement or dispute.
· "Formal" relates to official or conventional.
· "Normal" means usual or standard.
· Therefore, the most appropriate option is: (a) common. The completed sentence is: "Ravi has little in common with his friend, Senthil."