Concept:The phrase "go to one's head" refers to becoming excessively proud due to success or achievement.Explanation:The sentence says Ojo's learning has gone to his head.This idiom does not mean he has learnt too much or lost his mind.It means his educational achievement has made him arrogant or overly proud.Therefore, the most appropriate interpretation is that Ojo has become proud because of his learning.Answer:A. has become proud because of his learning